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authorLinus Torvalds2023-01-29 11:17:34 -0800
committerLinus Torvalds2023-01-29 11:17:34 -0800
commitbc6bc34b1095b64840308fa0fc325c028bd9b89a (patch)
treece845558eb16d73f86af683b53f9db756e1efd50 /arch/x86
parent80826e9020afc7b8243df302a13521e0020fa9d8 (diff)
parent27b5de622ea3fe0ad5a31a0ebd9f7a0a276932d1 (diff)
Merge tag 'x86_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov: - Start checking for -mindirect-branch-cs-prefix clang support too now that LLVM 16 will support it - Fix a NULL ptr deref when suspending with Xen PV - Have a SEV-SNP guest check explicitly for features enabled by the hypervisor and fail gracefully if some are unsupported by the guest instead of failing in a non-obvious and hard-to-debug way - Fix a MSI descriptor leakage under Xen - Mark Xen's MSI domain as supporting MSI-X - Prevent legacy PIC interrupts from being resent in software by marking them level triggered, as they should be, which lead to a NULL ptr deref * tag 'x86_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block acpi: Fix suspend with Xen PV x86/sev: Add SEV-SNP guest feature negotiation support x86/pci/xen: Fixup fallout from the PCI/MSI overhaul x86/pci/xen: Set MSI_FLAG_PCI_MSIX support in Xen MSI domain x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Makefile2
-rw-r--r--arch/x86/boot/compressed/ident_map_64.c6
-rw-r--r--arch/x86/boot/compressed/misc.h2
-rw-r--r--arch/x86/boot/compressed/sev.c70
-rw-r--r--arch/x86/include/asm/acpi.h8
-rw-r--r--arch/x86/include/asm/msr-index.h20
-rw-r--r--arch/x86/include/uapi/asm/svm.h6
-rw-r--r--arch/x86/kernel/i8259.c1
-rw-r--r--arch/x86/kernel/irqinit.c4
-rw-r--r--arch/x86/pci/xen.c2
10 files changed, 119 insertions, 2 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 9cf07322875a..73ed982d4100 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -14,13 +14,13 @@ endif
ifdef CONFIG_CC_IS_GCC
RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
-RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix)
RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
endif
ifdef CONFIG_CC_IS_CLANG
RETPOLINE_CFLAGS := -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS := -mretpoline
endif
+RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix)
ifdef CONFIG_RETHUNK
RETHUNK_CFLAGS := -mfunction-return=thunk-extern
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
index d4a314cc50d6..321a5011042d 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -180,6 +180,12 @@ void initialize_identity_maps(void *rmode)
/* Load the new page-table. */
write_cr3(top_level_pgt);
+
+ /*
+ * Now that the required page table mappings are established and a
+ * GHCB can be used, check for SNP guest/HV feature compatibility.
+ */
+ snp_check_features();
}
static pte_t *split_large_pmd(struct x86_mapping_info *info,
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 62208ec04ca4..20118fb7c53b 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -126,6 +126,7 @@ static inline void console_init(void)
#ifdef CONFIG_AMD_MEM_ENCRYPT
void sev_enable(struct boot_params *bp);
+void snp_check_features(void);
void sev_es_shutdown_ghcb(void);
extern bool sev_es_check_ghcb_fault(unsigned long address);
void snp_set_page_private(unsigned long paddr);
@@ -143,6 +144,7 @@ static inline void sev_enable(struct boot_params *bp)
if (bp)
bp->cc_blob_address = 0;
}
+static inline void snp_check_features(void) { }
static inline void sev_es_shutdown_ghcb(void) { }
static inline bool sev_es_check_ghcb_fault(unsigned long address)
{
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index c93930d5ccbd..d63ad8f99f83 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -208,6 +208,23 @@ void sev_es_shutdown_ghcb(void)
error("Can't unmap GHCB page");
}
+static void __noreturn sev_es_ghcb_terminate(struct ghcb *ghcb, unsigned int set,
+ unsigned int reason, u64 exit_info_2)
+{
+ u64 exit_info_1 = SVM_VMGEXIT_TERM_REASON(set, reason);
+
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_TERM_REQUEST);
+ ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+ ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ while (true)
+ asm volatile("hlt\n" : : : "memory");
+}
+
bool sev_es_check_ghcb_fault(unsigned long address)
{
/* Check whether the fault was on the GHCB page */
@@ -270,6 +287,59 @@ static void enforce_vmpl0(void)
sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0);
}
+/*
+ * SNP_FEATURES_IMPL_REQ is the mask of SNP features that will need
+ * guest side implementation for proper functioning of the guest. If any
+ * of these features are enabled in the hypervisor but are lacking guest
+ * side implementation, the behavior of the guest will be undefined. The
+ * guest could fail in non-obvious way making it difficult to debug.
+ *
+ * As the behavior of reserved feature bits is unknown to be on the
+ * safe side add them to the required features mask.
+ */
+#define SNP_FEATURES_IMPL_REQ (MSR_AMD64_SNP_VTOM | \
+ MSR_AMD64_SNP_REFLECT_VC | \
+ MSR_AMD64_SNP_RESTRICTED_INJ | \
+ MSR_AMD64_SNP_ALT_INJ | \
+ MSR_AMD64_SNP_DEBUG_SWAP | \
+ MSR_AMD64_SNP_VMPL_SSS | \
+ MSR_AMD64_SNP_SECURE_TSC | \
+ MSR_AMD64_SNP_VMGEXIT_PARAM | \
+ MSR_AMD64_SNP_VMSA_REG_PROTECTION | \
+ MSR_AMD64_SNP_RESERVED_BIT13 | \
+ MSR_AMD64_SNP_RESERVED_BIT15 | \
+ MSR_AMD64_SNP_RESERVED_MASK)
+
+/*
+ * SNP_FEATURES_PRESENT is the mask of SNP features that are implemented
+ * by the guest kernel. As and when a new feature is implemented in the
+ * guest kernel, a corresponding bit should be added to the mask.
+ */
+#define SNP_FEATURES_PRESENT (0)
+
+void snp_check_features(void)
+{
+ u64 unsupported;
+
+ if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+ return;
+
+ /*
+ * Terminate the boot if hypervisor has enabled any feature lacking
+ * guest side implementation. Pass on the unsupported features mask through
+ * EXIT_INFO_2 of the GHCB protocol so that those features can be reported
+ * as part of the guest boot failure.
+ */
+ unsupported = sev_status & SNP_FEATURES_IMPL_REQ & ~SNP_FEATURES_PRESENT;
+ if (unsupported) {
+ if (ghcb_version < 2 || (!boot_ghcb && !early_setup_ghcb()))
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+ sev_es_ghcb_terminate(boot_ghcb, SEV_TERM_SET_GEN,
+ GHCB_SNP_UNSUPPORTED, unsupported);
+ }
+}
+
void sev_enable(struct boot_params *bp)
{
unsigned int eax, ebx, ecx, edx;
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 65064d9f7fa6..8eb74cf386db 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -14,6 +14,7 @@
#include <asm/mmu.h>
#include <asm/mpspec.h>
#include <asm/x86_init.h>
+#include <asm/cpufeature.h>
#ifdef CONFIG_ACPI_APEI
# include <asm/pgtable_types.h>
@@ -63,6 +64,13 @@ extern int (*acpi_suspend_lowlevel)(void);
/* Physical address to resume after wakeup */
unsigned long acpi_get_wakeup_address(void);
+static inline bool acpi_skip_set_wakeup_address(void)
+{
+ return cpu_feature_enabled(X86_FEATURE_XENPV);
+}
+
+#define acpi_skip_set_wakeup_address acpi_skip_set_wakeup_address
+
/*
* Check if the CPU can handle C2 and deeper
*/
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 37ff47552bcb..d3fe82c5d6b6 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -566,6 +566,26 @@
#define MSR_AMD64_SEV_ES_ENABLED BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT)
#define MSR_AMD64_SEV_SNP_ENABLED BIT_ULL(MSR_AMD64_SEV_SNP_ENABLED_BIT)
+/* SNP feature bits enabled by the hypervisor */
+#define MSR_AMD64_SNP_VTOM BIT_ULL(3)
+#define MSR_AMD64_SNP_REFLECT_VC BIT_ULL(4)
+#define MSR_AMD64_SNP_RESTRICTED_INJ BIT_ULL(5)
+#define MSR_AMD64_SNP_ALT_INJ BIT_ULL(6)
+#define MSR_AMD64_SNP_DEBUG_SWAP BIT_ULL(7)
+#define MSR_AMD64_SNP_PREVENT_HOST_IBS BIT_ULL(8)
+#define MSR_AMD64_SNP_BTB_ISOLATION BIT_ULL(9)
+#define MSR_AMD64_SNP_VMPL_SSS BIT_ULL(10)
+#define MSR_AMD64_SNP_SECURE_TSC BIT_ULL(11)
+#define MSR_AMD64_SNP_VMGEXIT_PARAM BIT_ULL(12)
+#define MSR_AMD64_SNP_IBS_VIRT BIT_ULL(14)
+#define MSR_AMD64_SNP_VMSA_REG_PROTECTION BIT_ULL(16)
+#define MSR_AMD64_SNP_SMT_PROTECTION BIT_ULL(17)
+
+/* SNP feature bits reserved for future use. */
+#define MSR_AMD64_SNP_RESERVED_BIT13 BIT_ULL(13)
+#define MSR_AMD64_SNP_RESERVED_BIT15 BIT_ULL(15)
+#define MSR_AMD64_SNP_RESERVED_MASK GENMASK_ULL(63, 18)
+
#define MSR_AMD64_VIRT_SPEC_CTRL 0xc001011f
/* AMD Collaborative Processor Performance Control MSRs */
diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h
index f69c168391aa..80e1df482337 100644
--- a/arch/x86/include/uapi/asm/svm.h
+++ b/arch/x86/include/uapi/asm/svm.h
@@ -116,6 +116,12 @@
#define SVM_VMGEXIT_AP_CREATE 1
#define SVM_VMGEXIT_AP_DESTROY 2
#define SVM_VMGEXIT_HV_FEATURES 0x8000fffd
+#define SVM_VMGEXIT_TERM_REQUEST 0x8000fffe
+#define SVM_VMGEXIT_TERM_REASON(reason_set, reason_code) \
+ /* SW_EXITINFO1[3:0] */ \
+ (((((u64)reason_set) & 0xf)) | \
+ /* SW_EXITINFO1[11:4] */ \
+ ((((u64)reason_code) & 0xff) << 4))
#define SVM_VMGEXIT_UNSUPPORTED_EVENT 0x8000ffff
/* Exit code reserved for hypervisor/software use */
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
index 3aa5304200c5..4d8aff05a509 100644
--- a/arch/x86/kernel/i8259.c
+++ b/arch/x86/kernel/i8259.c
@@ -114,6 +114,7 @@ static void make_8259A_irq(unsigned int irq)
disable_irq_nosync(irq);
io_apic_irqs &= ~(1<<irq);
irq_set_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
+ irq_set_status_flags(irq, IRQ_LEVEL);
enable_irq(irq);
lapic_assign_legacy_vector(irq, true);
}
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index beb1bada1b0a..c683666876f1 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -65,8 +65,10 @@ void __init init_ISA_irqs(void)
legacy_pic->init(0);
- for (i = 0; i < nr_legacy_irqs(); i++)
+ for (i = 0; i < nr_legacy_irqs(); i++) {
irq_set_chip_and_handler(i, chip, handle_level_irq);
+ irq_set_status_flags(i, IRQ_LEVEL);
+ }
}
void __init init_IRQ(void)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index b94f727251b6..8babce71915f 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -392,6 +392,7 @@ static void xen_teardown_msi_irqs(struct pci_dev *dev)
msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_ASSOCIATED) {
for (i = 0; i < msidesc->nvec_used; i++)
xen_destroy_irq(msidesc->irq + i);
+ msidesc->irq = 0;
}
}
@@ -433,6 +434,7 @@ static struct msi_domain_ops xen_pci_msi_domain_ops = {
};
static struct msi_domain_info xen_pci_msi_domain_info = {
+ .flags = MSI_FLAG_PCI_MSIX | MSI_FLAG_FREE_MSI_DESCS | MSI_FLAG_DEV_SYSFS,
.ops = &xen_pci_msi_domain_ops,
};