From 0cc4f6d9f0b9f20f3f1e1149bdb6737c0b4e134a Mon Sep 17 00:00:00 2001
From: Tianyu Lan
Date: Mon, 25 Oct 2021 08:21:06 -0400
Subject: x86/hyperv: Initialize GHCB page in Isolation VM

Hyperv exposes GHCB page via SEV ES GHCB MSR for SNP guest
to communicate with hypervisor. Map GHCB page for all
cpus to read/write MSR register and submit hvcall request
via ghcb page.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-2-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 include/asm-generic/mshyperv.h | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'include')

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index d3eae6cdbacb..2d88aa855f7e 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -254,12 +254,18 @@ bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);
 enum hv_isolation_type hv_get_isolation_type(void);
 bool hv_is_isolation_supported(void);
+bool hv_isolation_type_snp(void);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
 #else /* CONFIG_HYPERV */
 static inline bool hv_is_hyperv_initialized(void) { return false; }
 static inline bool hv_is_hibernation_supported(void) { return false; }
 static inline void hyperv_cleanup(void) {}
+static inline bool hv_is_isolation_supported(void) { return false; }
+static inline enum hv_isolation_type hv_get_isolation_type(void)
+{
+	return HV_ISOLATION_TYPE_NONE;
+}
 #endif /* CONFIG_HYPERV */
 
 #endif
-- 
cgit v1.2.3


From af788f355e343373490b7d2e361016e7c24a0ffa Mon Sep 17 00:00:00 2001
From: Tianyu Lan
Date: Mon, 25 Oct 2021 08:21:07 -0400
Subject: x86/hyperv: Initialize shared memory boundary in the Isolation VM.

Hyper-V exposes shared memory boundary via cpuid
HYPERV_CPUID_ISOLATION_CONFIG and store it in the
shared_gpa_boundary of ms_hyperv struct. This prepares
to share memory with host for SNP guest.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-3-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/kernel/cpu/mshyperv.c |  2 ++
 include/asm-generic/mshyperv.h | 12 +++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

(limited to 'include')

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index b09ade389040..4794b716ec79 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -313,6 +313,8 @@ static void __init ms_hyperv_init_platform(void)
 	if (ms_hyperv.priv_high & HV_ISOLATION) {
 		ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
 		ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+		ms_hyperv.shared_gpa_boundary =
+			BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
 
 		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
 			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 2d88aa855f7e..a8ac497167d2 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -35,7 +35,17 @@ struct ms_hyperv_info {
 	u32 max_vp_index;
 	u32 max_lp_index;
 	u32 isolation_config_a;
-	u32 isolation_config_b;
+	union {
+		u32 isolation_config_b;
+		struct {
+			u32 cvm_type : 4;
+			u32 reserved1 : 1;
+			u32 shared_gpa_boundary_active : 1;
+			u32 shared_gpa_boundary_bits : 6;
+			u32 reserved2 : 20;
+		};
+	};
+	u64 shared_gpa_boundary;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
-- 
cgit v1.2.3


From 810a521265023a1d5c6c081ea2d216bc63d422f5 Mon Sep 17 00:00:00 2001
From: Tianyu Lan
Date: Mon, 25 Oct 2021 08:21:08 -0400
Subject: x86/hyperv: Add new hvcall guest address host visibility support

Add new hvcall guest address host visibility support to mark
memory visible to host. Call it inside set_memory_decrypted
/encrypted(). Add HYPERVISOR feature check in the
hv_is_isolation_supported() to optimize in non-virtualization
environment.

Acked-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-4-ltykernel@gmail.com
[ wei: fix conflicts with tip ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/hv_init.c          |   6 +++
 arch/x86/hyperv/ivm.c              | 105 +++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  17 ++++++
 arch/x86/include/asm/mshyperv.h    |   7 ++-
 arch/x86/mm/pat/set_memory.c       |  23 ++++++--
 include/asm-generic/hyperv-tlfs.h  |   1 +
 7 files changed, 154 insertions(+), 7 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c

(limited to 'include')

diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile
index 48e2c51464e8..5d2de10809ae 100644
--- a/arch/x86/hyperv/Makefile
+++ b/arch/x86/hyperv/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-y			:= hv_init.o mmu.o nested.o irqdomain.o
+obj-y			:= hv_init.o mmu.o nested.o irqdomain.o ivm.o
 obj-$(CONFIG_X86_64)	+= hv_apic.o hv_proc.o
 
 ifdef CONFIG_X86_64
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index a7e922755ad1..d57df6825527 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -603,6 +603,12 @@ EXPORT_SYMBOL_GPL(hv_get_isolation_type);
 
 bool hv_is_isolation_supported(void)
 {
+	if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+		return false;
+
+	if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
+		return false;
+
 	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
 }
 
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
new file mode 100644
index 000000000000..79e7fb83472a
--- /dev/null
+++ b/arch/x86/hyperv/ivm.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hyper-V Isolation VM interface with paravisor and hypervisor
+ *
+ * Author:
+ *  Tianyu Lan <Tianyu.Lan@microsoft.com>
+ */
+
+#include <linux/hyperv.h>
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <asm/mshyperv.h>
+
+/*
+ * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
+ *
+ * In Isolation VM, all guest memory is encrypted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host.
+ */
+static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
+			   enum hv_mem_host_visibility visibility)
+{
+	struct hv_gpa_range_for_visibility **input_pcpu, *input;
+	u16 pages_processed;
+	u64 hv_status;
+	unsigned long flags;
+
+	/* no-op if partition isolation is not enabled */
+	if (!hv_is_isolation_supported())
+		return 0;
+
+	if (count > HV_MAX_MODIFY_GPA_REP_COUNT) {
+		pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count,
+			HV_MAX_MODIFY_GPA_REP_COUNT);
+		return -EINVAL;
+	}
+
+	local_irq_save(flags);
+	input_pcpu = (struct hv_gpa_range_for_visibility **)
+			this_cpu_ptr(hyperv_pcpu_input_arg);
+	input = *input_pcpu;
+	if (unlikely(!input)) {
+		local_irq_restore(flags);
+		return -EINVAL;
+	}
+
+	input->partition_id = HV_PARTITION_ID_SELF;
+	input->host_visibility = visibility;
+	input->reserved0 = 0;
+	input->reserved1 = 0;
+	memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
+	hv_status = hv_do_rep_hypercall(
+			HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
+			0, input, &pages_processed);
+	local_irq_restore(flags);
+
+	if (hv_result_success(hv_status))
+		return 0;
+	else
+		return -EFAULT;
+}
+
+/*
+ * hv_set_mem_host_visibility - Set specified memory visible to host.
+ *
+ * In Isolation VM, all guest memory is encrypted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host. This function works as wrap of hv_mark_gpa_visibility()
+ * with memory base and size.
+ */
+int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visible)
+{
+	enum hv_mem_host_visibility visibility = visible ?
+			VMBUS_PAGE_VISIBLE_READ_WRITE : VMBUS_PAGE_NOT_VISIBLE;
+	u64 *pfn_array;
+	int ret = 0;
+	int i, pfn;
+
+	if (!hv_is_isolation_supported() || !hv_hypercall_pg)
+		return 0;
+
+	pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+	if (!pfn_array)
+		return -ENOMEM;
+
+	for (i = 0, pfn = 0; i < pagecount; i++) {
+		pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE);
+		pfn++;
+
+		if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
+			ret = hv_mark_gpa_visibility(pfn, pfn_array,
+						     visibility);
+			if (ret)
+				goto err_free_pfn_array;
+			pfn = 0;
+		}
+	}
+
+ err_free_pfn_array:
+	kfree(pfn_array);
+	return ret;
+}
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 2322d6bd5883..381e88122a5f 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -276,6 +276,23 @@ enum hv_isolation_type {
 #define HV_X64_MSR_TIME_REF_COUNT	HV_REGISTER_TIME_REF_COUNT
 #define HV_X64_MSR_REFERENCE_TSC	HV_REGISTER_REFERENCE_TSC
 
+/* Hyper-V memory host visibility */
+enum hv_mem_host_visibility {
+	VMBUS_PAGE_NOT_VISIBLE		= 0,
+	VMBUS_PAGE_VISIBLE_READ_ONLY	= 1,
+	VMBUS_PAGE_VISIBLE_READ_WRITE	= 3
+};
+
+/* HvCallModifySparseGpaPageHostVisibility hypercall */
+#define HV_MAX_MODIFY_GPA_REP_COUNT	((PAGE_SIZE / sizeof(u64)) - 2)
+struct hv_gpa_range_for_visibility {
+	u64 partition_id;
+	u32 host_visibility:2;
+	u32 reserved0:30;
+	u32 reserved1;
+	u64 gpa_page_list[HV_MAX_MODIFY_GPA_REP_COUNT];
+} __packed;
+
 /*
  * Declare the MSR used to setup pages used to communicate with the hypervisor.
  */
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 37739a277ac6..f3154ca41ac4 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -192,7 +192,7 @@ struct irq_domain *hv_create_pci_msi_domain(void);
 int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
 		struct hv_interrupt_entry *entry);
 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
-
+int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +209,11 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
 {
 	return -1;
 }
+static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
+					     bool visible)
+{
+	return -1;
+}
 #endif /* CONFIG_HYPERV */
 
 
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 527957586f3c..934dc5b2df36 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -30,6 +30,8 @@
 #include <asm/proto.h>
 #include <asm/memtype.h>
 #include <asm/set_memory.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
 
 #include "../mm_internal.h"
 
@@ -1981,15 +1983,15 @@ int set_memory_global(unsigned long addr, int numpages)
 				    __pgprot(_PAGE_GLOBAL), 0);
 }
 
-static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+/*
+ * __set_memory_enc_pgtable() is used for the hypervisors that get
+ * informed about "encryption" status via page tables.
+ */
+static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
 {
 	struct cpa_data cpa;
 	int ret;
 
-	/* Nothing to do if memory encryption is not active */
-	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
-		return 0;
-
 	/* Should not be working on unaligned addresses */
 	if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
 		addr &= PAGE_MASK;
@@ -2024,6 +2026,17 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	return ret;
 }
 
+static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+{
+	if (hv_is_isolation_supported())
+		return hv_set_mem_host_visibility(addr, numpages, !enc);
+
+	if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
+		return __set_memory_enc_pgtable(addr, numpages, enc);
+
+	return 0;
+}
+
 int set_memory_encrypted(unsigned long addr, int numpages)
 {
 	return __set_memory_enc_dec(addr, numpages, true);
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 56348a541c50..8ed6733d5146 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -158,6 +158,7 @@ struct ms_hyperv_tsc_page {
 #define HVCALL_RETARGET_INTERRUPT		0x007e
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
+#define HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY 0x00db
 
 /* Extended hypercalls */
 #define HV_EXT_CALL_QUERY_CAPABILITIES		0x8001
-- 
cgit v1.2.3


From d4dccf353db80e209f262e3973c834e6e48ba9a9 Mon Sep 17 00:00:00 2001
From: Tianyu Lan
Date: Mon, 25 Oct 2021 08:21:09 -0400
Subject: Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in
 Isolation VM

Mark vmbus ring buffer visible with set_memory_decrypted() when
establish gpadl handle.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-5-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel.c            | 53 +++++++++++++++++++++++++++++------------
 drivers/net/hyperv/hyperv_net.h |  5 ++--
 drivers/net/hyperv/netvsc.c     | 15 ++++++------
 drivers/uio/uio_hv_generic.c    | 18 +++++++-------
 include/linux/hyperv.h          | 12 +++++++---
 5 files changed, 65 insertions(+), 38 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f3761c73b074..b37ff4a39224 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -17,6 +17,7 @@
 #include <linux/hyperv.h>
 #include <linux/uio.h>
 #include <linux/interrupt.h>
+#include <linux/set_memory.h>
 #include <asm/page.h>
 #include <asm/mshyperv.h>
 
@@ -456,7 +457,7 @@ nomem:
 static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 				   enum hv_gpadl_type type, void *kbuffer,
 				   u32 size, u32 send_offset,
-				   u32 *gpadl_handle)
+				   struct vmbus_gpadl *gpadl)
 {
 	struct vmbus_channel_gpadl_header *gpadlmsg;
 	struct vmbus_channel_gpadl_body *gpadl_body;
@@ -474,6 +475,15 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	if (ret)
 		return ret;
 
+	ret = set_memory_decrypted((unsigned long)kbuffer,
+				   PFN_UP(size));
+	if (ret) {
+		dev_warn(&channel->device_obj->device,
+			 "Failed to set host visibility for new GPADL %d.\n",
+			 ret);
+		return ret;
+	}
+
 	init_completion(&msginfo->waitevent);
 	msginfo->waiting_channel = channel;
 
@@ -537,7 +547,10 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	}
 
 	/* At this point, we received the gpadl created msg */
-	*gpadl_handle = gpadlmsg->gpadl;
+	gpadl->gpadl_handle = gpadlmsg->gpadl;
+	gpadl->buffer = kbuffer;
+	gpadl->size = size;
+
 
 cleanup:
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
@@ -549,6 +562,11 @@ cleanup:
 	}
 
 	kfree(msginfo);
+
+	if (ret)
+		set_memory_encrypted((unsigned long)kbuffer,
+				     PFN_UP(size));
+
 	return ret;
 }
 
@@ -561,10 +579,10 @@ cleanup:
  * @gpadl_handle: some funky thing
  */
 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
-			  u32 size, u32 *gpadl_handle)
+			  u32 size, struct vmbus_gpadl *gpadl)
 {
 	return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size,
-				       0U, gpadl_handle);
+				       0U, gpadl);
 }
 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 
@@ -675,7 +693,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
 		goto error_clean_ring;
 
 	/* Establish the gpadl for the ring buffer */
-	newchannel->ringbuffer_gpadlhandle = 0;
+	newchannel->ringbuffer_gpadlhandle.gpadl_handle = 0;
 
 	err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING,
 				      page_address(newchannel->ringbuffer_page),
@@ -701,7 +719,8 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
 	open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 	open_msg->openid = newchannel->offermsg.child_relid;
 	open_msg->child_relid = newchannel->offermsg.child_relid;
-	open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
+	open_msg->ringbuffer_gpadlhandle
+		= newchannel->ringbuffer_gpadlhandle.gpadl_handle;
 	/*
 	 * The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and
 	 * the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so
@@ -759,8 +778,7 @@ error_clean_msglist:
 error_free_info:
 	kfree(open_info);
 error_free_gpadl:
-	vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
-	newchannel->ringbuffer_gpadlhandle = 0;
+	vmbus_teardown_gpadl(newchannel, &newchannel->ringbuffer_gpadlhandle);
 error_clean_ring:
 	hv_ringbuffer_cleanup(&newchannel->outbound);
 	hv_ringbuffer_cleanup(&newchannel->inbound);
@@ -806,7 +824,7 @@ EXPORT_SYMBOL_GPL(vmbus_open);
 /*
  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
  */
-int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
+int vmbus_teardown_gpadl(struct vmbus_channel *channel, struct vmbus_gpadl *gpadl)
 {
 	struct vmbus_channel_gpadl_teardown *msg;
 	struct vmbus_channel_msginfo *info;
@@ -825,7 +843,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 
 	msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 	msg->child_relid = channel->offermsg.child_relid;
-	msg->gpadl = gpadl_handle;
+	msg->gpadl = gpadl->gpadl_handle;
 
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_add_tail(&info->msglistentry,
@@ -845,6 +863,8 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 
 	wait_for_completion(&info->waitevent);
 
+	gpadl->gpadl_handle = 0;
+
 post_msg_err:
 	/*
 	 * If the channel has been rescinded;
@@ -859,6 +879,12 @@ post_msg_err:
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
 	kfree(info);
+
+	ret = set_memory_encrypted((unsigned long)gpadl->buffer,
+				   PFN_UP(gpadl->size));
+	if (ret)
+		pr_warn("Fail to set mem host visibility in GPADL teardown %d.\n", ret);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
@@ -933,9 +959,8 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 	}
 
 	/* Tear down the gpadl for the channel's ring buffer */
-	else if (channel->ringbuffer_gpadlhandle) {
-		ret = vmbus_teardown_gpadl(channel,
-					   channel->ringbuffer_gpadlhandle);
+	else if (channel->ringbuffer_gpadlhandle.gpadl_handle) {
+		ret = vmbus_teardown_gpadl(channel, &channel->ringbuffer_gpadlhandle);
 		if (ret) {
 			pr_err("Close failed: teardown gpadl return %d\n", ret);
 			/*
@@ -943,8 +968,6 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 			 * it is perhaps better to leak memory.
 			 */
 		}
-
-		channel->ringbuffer_gpadlhandle = 0;
 	}
 
 	if (!ret)
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index bc48855dff10..315278a7cf88 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1075,14 +1075,15 @@ struct netvsc_device {
 	/* Receive buffer allocated by us but manages by NetVSP */
 	void *recv_buf;
 	u32 recv_buf_size; /* allocated bytes */
-	u32 recv_buf_gpadl_handle;
+	struct vmbus_gpadl recv_buf_gpadl_handle;
 	u32 recv_section_cnt;
 	u32 recv_section_size;
 	u32 recv_completion_cnt;
 
 	/* Send buffer allocated by us */
 	void *send_buf;
-	u32 send_buf_gpadl_handle;
+	u32 send_buf_size;
+	struct vmbus_gpadl send_buf_gpadl_handle;
 	u32 send_section_cnt;
 	u32 send_section_size;
 	unsigned long *send_section_map;
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7bd935412853..396bc1c204e6 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -278,9 +278,9 @@ static void netvsc_teardown_recv_gpadl(struct hv_device *device,
 {
 	int ret;
 
-	if (net_device->recv_buf_gpadl_handle) {
+	if (net_device->recv_buf_gpadl_handle.gpadl_handle) {
 		ret = vmbus_teardown_gpadl(device->channel,
-					   net_device->recv_buf_gpadl_handle);
+					   &net_device->recv_buf_gpadl_handle);
 
 		/* If we failed here, we might as well return and have a leak
 		 * rather than continue and a bugchk
@@ -290,7 +290,6 @@ static void netvsc_teardown_recv_gpadl(struct hv_device *device,
 				   "unable to teardown receive buffer's gpadl\n");
 			return;
 		}
-		net_device->recv_buf_gpadl_handle = 0;
 	}
 }
 
@@ -300,9 +299,9 @@ static void netvsc_teardown_send_gpadl(struct hv_device *device,
 {
 	int ret;
 
-	if (net_device->send_buf_gpadl_handle) {
+	if (net_device->send_buf_gpadl_handle.gpadl_handle) {
 		ret = vmbus_teardown_gpadl(device->channel,
-					   net_device->send_buf_gpadl_handle);
+					   &net_device->send_buf_gpadl_handle);
 
 		/* If we failed here, we might as well return and have a leak
 		 * rather than continue and a bugchk
@@ -312,7 +311,6 @@ static void netvsc_teardown_send_gpadl(struct hv_device *device,
 				   "unable to teardown send buffer's gpadl\n");
 			return;
 		}
-		net_device->send_buf_gpadl_handle = 0;
 	}
 }
 
@@ -380,7 +378,7 @@ static int netvsc_init_buf(struct hv_device *device,
 	memset(init_packet, 0, sizeof(struct nvsp_message));
 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 	init_packet->msg.v1_msg.send_recv_buf.
-		gpadl_handle = net_device->recv_buf_gpadl_handle;
+		gpadl_handle = net_device->recv_buf_gpadl_handle.gpadl_handle;
 	init_packet->msg.v1_msg.
 		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 
@@ -463,6 +461,7 @@ static int netvsc_init_buf(struct hv_device *device,
 		ret = -ENOMEM;
 		goto cleanup;
 	}
+	net_device->send_buf_size = buf_size;
 
 	/* Establish the gpadl handle for this buffer on this
 	 * channel.  Note: This call uses the vmbus connection rather
@@ -482,7 +481,7 @@ static int netvsc_init_buf(struct hv_device *device,
 	memset(init_packet, 0, sizeof(struct nvsp_message));
 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
-		net_device->send_buf_gpadl_handle;
+		net_device->send_buf_gpadl_handle.gpadl_handle;
 	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 
 	trace_nvsp_send(ndev, init_packet);
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 652fe2547587..c08a6cfd119f 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -58,11 +58,11 @@ struct hv_uio_private_data {
 	atomic_t refcnt;
 
 	void	*recv_buf;
-	u32	recv_gpadl;
+	struct vmbus_gpadl recv_gpadl;
 	char	recv_name[32];	/* "recv_4294967295" */
 
 	void	*send_buf;
-	u32	send_gpadl;
+	struct vmbus_gpadl send_gpadl;
 	char	send_name[32];
 };
 
@@ -179,15 +179,13 @@ hv_uio_new_channel(struct vmbus_channel *new_sc)
 static void
 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
 {
-	if (pdata->send_gpadl) {
-		vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
-		pdata->send_gpadl = 0;
+	if (pdata->send_gpadl.gpadl_handle) {
+		vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl);
 		vfree(pdata->send_buf);
 	}
 
-	if (pdata->recv_gpadl) {
-		vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
-		pdata->recv_gpadl = 0;
+	if (pdata->recv_gpadl.gpadl_handle) {
+		vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl);
 		vfree(pdata->recv_buf);
 	}
 }
@@ -303,7 +301,7 @@ hv_uio_probe(struct hv_device *dev,
 
 	/* put Global Physical Address Label in name */
 	snprintf(pdata->recv_name, sizeof(pdata->recv_name),
-		 "recv:%u", pdata->recv_gpadl);
+		 "recv:%u", pdata->recv_gpadl.gpadl_handle);
 	pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
 	pdata->info.mem[RECV_BUF_MAP].addr
 		= (uintptr_t)pdata->recv_buf;
@@ -324,7 +322,7 @@ hv_uio_probe(struct hv_device *dev,
 	}
 
 	snprintf(pdata->send_name, sizeof(pdata->send_name),
-		 "send:%u", pdata->send_gpadl);
+		 "send:%u", pdata->send_gpadl.gpadl_handle);
 	pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
 	pdata->info.mem[SEND_BUF_MAP].addr
 		= (uintptr_t)pdata->send_buf;
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index ddc8713ce57b..a9e0bc3b1511 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -803,6 +803,12 @@ struct vmbus_device {
 
 #define VMBUS_DEFAULT_MAX_PKT_SIZE 4096
 
+struct vmbus_gpadl {
+	u32 gpadl_handle;
+	u32 size;
+	void *buffer;
+};
+
 struct vmbus_channel {
 	struct list_head listentry;
 
@@ -822,7 +828,7 @@ struct vmbus_channel {
 	bool rescind_ref; /* got rescind msg, got channel reference */
 	struct completion rescind_event;
 
-	u32 ringbuffer_gpadlhandle;
+	struct vmbus_gpadl ringbuffer_gpadlhandle;
 
 	/* Allocated memory for ring buffer */
 	struct page *ringbuffer_page;
@@ -1192,10 +1198,10 @@ extern int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 extern int vmbus_establish_gpadl(struct vmbus_channel *channel,
 				      void *kbuffer,
 				      u32 size,
-				      u32 *gpadl_handle);
+				      struct vmbus_gpadl *gpadl);
 
 extern int vmbus_teardown_gpadl(struct vmbus_channel *channel,
-				     u32 gpadl_handle);
+				     struct vmbus_gpadl *gpadl);
 
 void vmbus_reset_channel_cb(struct vmbus_channel *channel);
 
-- 
cgit v1.2.3


From faff44069ff538ccdfef187c4d7ec83d22dfb3a4 Mon Sep 17 00:00:00 2001
From: Tianyu Lan
Date: Mon, 25 Oct 2021 08:21:11 -0400
Subject: x86/hyperv: Add Write/Read MSR registers via ghcb page

Hyperv provides GHCB protocol to write Synthetic Interrupt
Controller MSR registers in Isolation VM with AMD SEV SNP
and these registers are emulated by hypervisor directly.
Hyperv requires to write SINTx MSR registers twice. First
writes MSR via GHCB page to communicate with hypervisor
and then writes wrmsr instruction to talk with paravisor
which runs in VMPL0. Guest OS ID MSR also needs to be set
via GHCB page.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-7-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/hyperv/hv_init.c       |  36 +++----------
 arch/x86/hyperv/ivm.c           | 111 ++++++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h |  63 ++++++++++++++++++-----
 drivers/hv/hv.c                 |  74 +++++++++++++++++++++------
 drivers/hv/hv_common.c          |   6 +++
 include/asm-generic/mshyperv.h  |   1 +
 6 files changed, 232 insertions(+), 59 deletions(-)

(limited to 'include')

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index d57df6825527..a16a83e46a30 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -37,7 +37,7 @@ EXPORT_SYMBOL_GPL(hv_current_partition_id);
 void *hv_hypercall_pg;
 EXPORT_SYMBOL_GPL(hv_hypercall_pg);
 
-void __percpu **hv_ghcb_pg;
+union hv_ghcb __percpu **hv_ghcb_pg;
 
 /* Storage to save the hypercall page temporarily for hibernation */
 static void *hv_hypercall_pg_saved;
@@ -406,7 +406,7 @@ void __init hyperv_init(void)
 	}
 
 	if (hv_isolation_type_snp()) {
-		hv_ghcb_pg = alloc_percpu(void *);
+		hv_ghcb_pg = alloc_percpu(union hv_ghcb *);
 		if (!hv_ghcb_pg)
 			goto free_vp_assist_page;
 	}
@@ -424,6 +424,9 @@ void __init hyperv_init(void)
 	guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
 
+	/* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
+	hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
 	hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
 			VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
 			VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
@@ -501,6 +504,7 @@ void __init hyperv_init(void)
 
 clean_guest_os_id:
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+	hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
 	cpuhp_remove_state(cpuhp);
 free_ghcb_page:
 	free_percpu(hv_ghcb_pg);
@@ -522,6 +526,7 @@ void hyperv_cleanup(void)
 
 	/* Reset our OS id */
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+	hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
 
 	/*
 	 * Reset hypercall page reference before reset the page,
@@ -592,30 +597,3 @@ bool hv_is_hyperv_initialized(void)
 	return hypercall_msr.enable;
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
-
-enum hv_isolation_type hv_get_isolation_type(void)
-{
-	if (!(ms_hyperv.priv_high & HV_ISOLATION))
-		return HV_ISOLATION_TYPE_NONE;
-	return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
-}
-EXPORT_SYMBOL_GPL(hv_get_isolation_type);
-
-bool hv_is_isolation_supported(void)
-{
-	if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
-		return false;
-
-	if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
-		return false;
-
-	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
-}
-
-DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
-
-bool hv_isolation_type_snp(void)
-{
-	return static_branch_unlikely(&isolation_type_snp);
-}
-EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 79e7fb83472a..9c48d6e2d8b2 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -6,12 +6,123 @@
  *  Tianyu Lan <Tianyu.Lan@microsoft.com>
  */
 
+#include <linux/types.h>
+#include <linux/bitfield.h>
 #include <linux/hyperv.h>
 #include <linux/types.h>
 #include <linux/bitfield.h>
 #include <linux/slab.h>
+#include <asm/svm.h>
+#include <asm/sev.h>
 #include <asm/io.h>
 #include <asm/mshyperv.h>
+#include <asm/hypervisor.h>
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+union hv_ghcb {
+	struct ghcb ghcb;
+} __packed __aligned(HV_HYP_PAGE_SIZE);
+
+void hv_ghcb_msr_write(u64 msr, u64 value)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+	struct es_em_ctxt ctxt;
+
+	if (!hv_ghcb_pg)
+		return;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+	ghcb_set_rax(&hv_ghcb->ghcb, lower_32_bits(value));
+	ghcb_set_rdx(&hv_ghcb->ghcb, upper_32_bits(value));
+
+	if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, false, &ctxt,
+				SVM_EXIT_MSR, 1, 0))
+		pr_warn("Fail to write msr via ghcb %llx.\n", msr);
+
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_msr_write);
+
+void hv_ghcb_msr_read(u64 msr, u64 *value)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+	struct es_em_ctxt ctxt;
+
+	/* Check size of union hv_ghcb here. */
+	BUILD_BUG_ON(sizeof(union hv_ghcb) != HV_HYP_PAGE_SIZE);
+
+	if (!hv_ghcb_pg)
+		return;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+	if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, false, &ctxt,
+				SVM_EXIT_MSR, 0, 0))
+		pr_warn("Fail to read msr via ghcb %llx.\n", msr);
+	else
+		*value = (u64)lower_32_bits(hv_ghcb->ghcb.save.rax)
+			| ((u64)lower_32_bits(hv_ghcb->ghcb.save.rdx) << 32);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_msr_read);
+#endif
+
+enum hv_isolation_type hv_get_isolation_type(void)
+{
+	if (!(ms_hyperv.priv_high & HV_ISOLATION))
+		return HV_ISOLATION_TYPE_NONE;
+	return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
+}
+EXPORT_SYMBOL_GPL(hv_get_isolation_type);
+
+/*
+ * hv_is_isolation_supported - Check system runs in the Hyper-V
+ * isolation VM.
+ */
+bool hv_is_isolation_supported(void)
+{
+	if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+		return false;
+
+	if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
+		return false;
+
+	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
+}
+
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+/*
+ * hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
+ * isolation VM.
+ */
+bool hv_isolation_type_snp(void)
+{
+	return static_branch_unlikely(&isolation_type_snp);
+}
 
 /*
  * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f3154ca41ac4..da3972fe5a7a 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,25 +11,14 @@
 #include <asm/paravirt.h>
 #include <asm/mshyperv.h>
 
+union hv_ghcb;
+
 DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
 
 typedef int (*hyperv_fill_flush_list_func)(
 		struct hv_guest_mapping_flush_list *flush,
 		void *data);
 
-static inline void hv_set_register(unsigned int reg, u64 value)
-{
-	wrmsrl(reg, value);
-}
-
-static inline u64 hv_get_register(unsigned int reg)
-{
-	u64 value;
-
-	rdmsrl(reg, value);
-	return value;
-}
-
 #define hv_get_raw_timer() rdtsc_ordered()
 
 void hyperv_vector_handler(struct pt_regs *regs);
@@ -41,7 +30,7 @@ extern void *hv_hypercall_pg;
 
 extern u64 hv_current_partition_id;
 
-extern void __percpu **hv_ghcb_pg;
+extern union hv_ghcb  __percpu **hv_ghcb_pg;
 
 int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
 int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
@@ -193,6 +182,50 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
 		struct hv_interrupt_entry *entry);
 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
 int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+void hv_ghcb_msr_write(u64 msr, u64 value);
+void hv_ghcb_msr_read(u64 msr, u64 *value);
+#else
+static inline void hv_ghcb_msr_write(u64 msr, u64 value) {}
+static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {}
+#endif
+
+extern bool hv_isolation_type_snp(void);
+
+static inline bool hv_is_synic_reg(unsigned int reg)
+{
+	if ((reg >= HV_REGISTER_SCONTROL) &&
+	    (reg <= HV_REGISTER_SINT15))
+		return true;
+	return false;
+}
+
+static inline u64 hv_get_register(unsigned int reg)
+{
+	u64 value;
+
+	if (hv_is_synic_reg(reg) && hv_isolation_type_snp())
+		hv_ghcb_msr_read(reg, &value);
+	else
+		rdmsrl(reg, value);
+	return value;
+}
+
+static inline void hv_set_register(unsigned int reg, u64 value)
+{
+	if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) {
+		hv_ghcb_msr_write(reg, value);
+
+		/* Write proxy bit via wrmsl instruction */
+		if (reg >= HV_REGISTER_SINT0 &&
+		    reg <= HV_REGISTER_SINT15)
+			wrmsrl(reg, value | 1 << 20);
+	} else {
+		wrmsrl(reg, value);
+	}
+}
+
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +242,8 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
 {
 	return -1;
 }
+static inline void hv_set_register(unsigned int reg, u64 value) { }
+static inline u64 hv_get_register(unsigned int reg) { return 0; }
 static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
 					     bool visible)
 {
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index e83507f49676..943392db9e8a 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -8,6 +8,7 @@
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
@@ -136,17 +137,24 @@ int hv_synic_alloc(void)
 		tasklet_init(&hv_cpu->msg_dpc,
 			     vmbus_on_msg_dpc, (unsigned long) hv_cpu);
 
-		hv_cpu->synic_message_page =
-			(void *)get_zeroed_page(GFP_ATOMIC);
-		if (hv_cpu->synic_message_page == NULL) {
-			pr_err("Unable to allocate SYNIC message page\n");
-			goto err;
-		}
+		/*
+		 * Synic message and event pages are allocated by paravisor.
+		 * Skip these pages allocation here.
+		 */
+		if (!hv_isolation_type_snp()) {
+			hv_cpu->synic_message_page =
+				(void *)get_zeroed_page(GFP_ATOMIC);
+			if (hv_cpu->synic_message_page == NULL) {
+				pr_err("Unable to allocate SYNIC message page\n");
+				goto err;
+			}
 
-		hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
-		if (hv_cpu->synic_event_page == NULL) {
-			pr_err("Unable to allocate SYNIC event page\n");
-			goto err;
+			hv_cpu->synic_event_page =
+				(void *)get_zeroed_page(GFP_ATOMIC);
+			if (hv_cpu->synic_event_page == NULL) {
+				pr_err("Unable to allocate SYNIC event page\n");
+				goto err;
+			}
 		}
 
 		hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
@@ -201,16 +209,35 @@ void hv_synic_enable_regs(unsigned int cpu)
 	/* Setup the Synic's message page */
 	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
 	simp.simp_enabled = 1;
-	simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
-		>> HV_HYP_PAGE_SHIFT;
+
+	if (hv_isolation_type_snp()) {
+		hv_cpu->synic_message_page
+			= memremap(simp.base_simp_gpa << HV_HYP_PAGE_SHIFT,
+				   HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+		if (!hv_cpu->synic_message_page)
+			pr_err("Fail to map syinc message page.\n");
+	} else {
+		simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
+			>> HV_HYP_PAGE_SHIFT;
+	}
 
 	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
 
 	/* Setup the Synic's event page */
 	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
 	siefp.siefp_enabled = 1;
-	siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
-		>> HV_HYP_PAGE_SHIFT;
+
+	if (hv_isolation_type_snp()) {
+		hv_cpu->synic_event_page =
+			memremap(siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT,
+				 HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+
+		if (!hv_cpu->synic_event_page)
+			pr_err("Fail to map syinc event page.\n");
+	} else {
+		siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
+			>> HV_HYP_PAGE_SHIFT;
+	}
 
 	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
 
@@ -257,6 +284,8 @@ int hv_synic_init(unsigned int cpu)
  */
 void hv_synic_disable_regs(unsigned int cpu)
 {
+	struct hv_per_cpu_context *hv_cpu
+		= per_cpu_ptr(hv_context.cpu_context, cpu);
 	union hv_synic_sint shared_sint;
 	union hv_synic_simp simp;
 	union hv_synic_siefp siefp;
@@ -273,14 +302,27 @@ void hv_synic_disable_regs(unsigned int cpu)
 				shared_sint.as_uint64);
 
 	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+	/*
+	 * In Isolation VM, sim and sief pages are allocated by
+	 * paravisor. These pages also will be used by kdump
+	 * kernel. So just reset enable bit here and keep page
+	 * addresses.
+	 */
 	simp.simp_enabled = 0;
-	simp.base_simp_gpa = 0;
+	if (hv_isolation_type_snp())
+		memunmap(hv_cpu->synic_message_page);
+	else
+		simp.base_simp_gpa = 0;
 
 	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
 
 	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
 	siefp.siefp_enabled = 0;
-	siefp.base_siefp_gpa = 0;
+
+	if (hv_isolation_type_snp())
+		memunmap(hv_cpu->synic_event_page);
+	else
+		siefp.base_siefp_gpa = 0;
 
 	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
 
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index c0d9048a4112..1fc82d237161 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -249,6 +249,12 @@ bool __weak hv_is_isolation_supported(void)
 }
 EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
 
+bool __weak hv_isolation_type_snp(void)
+{
+	return false;
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
+
 void __weak hv_setup_vmbus_handler(void (*handler)(void))
 {
 }
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index a8ac497167d2..6d3ba902ebb0 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -54,6 +54,7 @@ extern void  __percpu  **hyperv_pcpu_output_arg;
 
 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
+extern bool hv_isolation_type_snp(void);
 
 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
 static inline int hv_result(u64 status)
-- 
cgit v1.2.3


From 20c89a559e00dfe352b73e867211a669113ae881 Mon Sep 17 00:00:00 2001
From: Tianyu Lan
Date: Mon, 25 Oct 2021 08:21:12 -0400
Subject: x86/hyperv: Add ghcb hvcall support for SNP VM

hyperv provides ghcb hvcall to handle VMBus
HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE
msg in SNP Isolation VM. Add such support.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-8-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/hyperv/ivm.c          | 75 ++++++++++++++++++++++++++++++++++++++++++
 drivers/hv/connection.c        |  6 +++-
 drivers/hv/hv.c                |  8 ++++-
 drivers/hv/hv_common.c         |  6 ++++
 include/asm-generic/mshyperv.h |  1 +
 5 files changed, 94 insertions(+), 2 deletions(-)

(limited to 'include')

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 9c48d6e2d8b2..4d012fd9d95d 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -19,10 +19,85 @@
 #include <asm/hypervisor.h>
 
 #ifdef CONFIG_AMD_MEM_ENCRYPT
+
+#define GHCB_USAGE_HYPERV_CALL	1
+
 union hv_ghcb {
 	struct ghcb ghcb;
+	struct {
+		u64 hypercalldata[509];
+		u64 outputgpa;
+		union {
+			union {
+				struct {
+					u32 callcode        : 16;
+					u32 isfast          : 1;
+					u32 reserved1       : 14;
+					u32 isnested        : 1;
+					u32 countofelements : 12;
+					u32 reserved2       : 4;
+					u32 repstartindex   : 12;
+					u32 reserved3       : 4;
+				};
+				u64 asuint64;
+			} hypercallinput;
+			union {
+				struct {
+					u16 callstatus;
+					u16 reserved1;
+					u32 elementsprocessed : 12;
+					u32 reserved2         : 20;
+				};
+				u64 asunit64;
+			} hypercalloutput;
+		};
+		u64 reserved2;
+	} hypercall;
 } __packed __aligned(HV_HYP_PAGE_SIZE);
 
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+	u64 status;
+
+	if (!hv_ghcb_pg)
+		return -EFAULT;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return -EFAULT;
+	}
+
+	hv_ghcb->ghcb.protocol_version = GHCB_PROTOCOL_MAX;
+	hv_ghcb->ghcb.ghcb_usage = GHCB_USAGE_HYPERV_CALL;
+
+	hv_ghcb->hypercall.outputgpa = (u64)output;
+	hv_ghcb->hypercall.hypercallinput.asuint64 = 0;
+	hv_ghcb->hypercall.hypercallinput.callcode = control;
+
+	if (input_size)
+		memcpy(hv_ghcb->hypercall.hypercalldata, input, input_size);
+
+	VMGEXIT();
+
+	hv_ghcb->ghcb.ghcb_usage = 0xffffffff;
+	memset(hv_ghcb->ghcb.save.valid_bitmap, 0,
+	       sizeof(hv_ghcb->ghcb.save.valid_bitmap));
+
+	status = hv_ghcb->hypercall.hypercalloutput.callstatus;
+
+	local_irq_restore(flags);
+
+	return status;
+}
+
 void hv_ghcb_msr_write(u64 msr, u64 value)
 {
 	union hv_ghcb *hv_ghcb;
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 5e479d54918c..8820ae68f20f 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -447,6 +447,10 @@ void vmbus_set_event(struct vmbus_channel *channel)
 
 	++channel->sig_events;
 
-	hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
+	if (hv_isolation_type_snp())
+		hv_ghcb_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event,
+				NULL, sizeof(channel->sig_event));
+	else
+		hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 943392db9e8a..4d6480d57546 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -98,7 +98,13 @@ int hv_post_message(union hv_connection_id connection_id,
 	aligned_msg->payload_size = payload_size;
 	memcpy((void *)aligned_msg->payload, payload, payload_size);
 
-	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
+	if (hv_isolation_type_snp())
+		status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE,
+				(void *)aligned_msg, NULL,
+				sizeof(*aligned_msg));
+	else
+		status = hv_do_hypercall(HVCALL_POST_MESSAGE,
+				aligned_msg, NULL);
 
 	/* Preemption must remain disabled until after the hypercall
 	 * so some other thread can't get scheduled onto this cpu and
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 1fc82d237161..7be173a99f27 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -289,3 +289,9 @@ void __weak hyperv_cleanup(void)
 {
 }
 EXPORT_SYMBOL_GPL(hyperv_cleanup);
+
+u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
+{
+	return HV_STATUS_INVALID_PARAMETER;
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 6d3ba902ebb0..3e2248ac328e 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -266,6 +266,7 @@ bool hv_is_hibernation_supported(void);
 enum hv_isolation_type hv_get_isolation_type(void);
 bool hv_is_isolation_supported(void);
 bool hv_isolation_type_snp(void);
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
 #else /* CONFIG_HYPERV */
-- 
cgit v1.2.3


From 20cf6616ccd50256a14fb2a7a3cc730080c90cd0 Mon Sep 17 00:00:00 2001
From: Michael Kelley
Date: Mon, 25 Oct 2021 12:54:34 -0700
Subject: Drivers: hv: vmbus: Remove unused code to check for subchannels

The last caller of vmbus_are_subchannels_present() was removed in commit
c967590457ca ("scsi: storvsc: Fix a race in sub-channel creation that can cause panic").

Remove this dead code, and the utility function invoke_sc_cb() that it is
the only caller of.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1635191674-34407-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel_mgmt.c | 34 ----------------------------------
 include/linux/hyperv.h    | 13 -------------
 2 files changed, 47 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 142308526ec6..2829575fd9b7 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1581,21 +1581,6 @@ cleanup:
 	return ret;
 }
 
-static void invoke_sc_cb(struct vmbus_channel *primary_channel)
-{
-	struct list_head *cur, *tmp;
-	struct vmbus_channel *cur_channel;
-
-	if (primary_channel->sc_creation_callback == NULL)
-		return;
-
-	list_for_each_safe(cur, tmp, &primary_channel->sc_list) {
-		cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
-
-		primary_channel->sc_creation_callback(cur_channel);
-	}
-}
-
 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
 				void (*sc_cr_cb)(struct vmbus_channel *new_sc))
 {
@@ -1603,25 +1588,6 @@ void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
 }
 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback);
 
-bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
-{
-	bool ret;
-
-	ret = !list_empty(&primary->sc_list);
-
-	if (ret) {
-		/*
-		 * Invoke the callback on sub-channel creation.
-		 * This will present a uniform interface to the
-		 * clients.
-		 */
-		invoke_sc_cb(primary);
-	}
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);
-
 void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel,
 		void (*chn_rescind_cb)(struct vmbus_channel *))
 {
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index a9e0bc3b1511..b823311eac79 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1106,19 +1106,6 @@ void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
 void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel,
 		void (*chn_rescind_cb)(struct vmbus_channel *));
 
-/*
- * Check if sub-channels have already been offerred. This API will be useful
- * when the driver is unloaded after establishing sub-channels. In this case,
- * when the driver is re-loaded, the driver would have to check if the
- * subchannels have already been established before attempting to request
- * the creation of sub-channels.
- * This function returns TRUE to indicate that subchannels have already been
- * created.
- * This function should be invoked after setting the callback function for
- * sub-channel creation.
- */
-bool vmbus_are_subchannels_present(struct vmbus_channel *primary);
-
 /* The format must be the same as struct vmdata_gpa_direct */
 struct vmbus_channel_packet_page_buffer {
 	u16 type;
-- 
cgit v1.2.3