virtio: replace arch_has_restricted_virtio_memory_access()

Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov <bp@suse.de>

5 files changed, 7 insertions, 19 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b1a88f6cc349..bf253628c136 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -768,7 +768,6 @@ menu "Virtualization"
 config PROTECTED_VIRTUALIZATION_GUEST
 	def_bool n
 	prompt "Protected virtualization guest support"
-	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 	help
 	  Select this option, if you want to be able to run this
 	  kernel as a protected virtualization KVM guest.
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 6fb6bf64326f..6a0ac00d5a42 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -31,6 +31,7 @@
 #include <linux/cma.h>
 #include <linux/gfp.h>
 #include <linux/dma-direct.h>
+#include <linux/platform-feature.h>
 #include <asm/processor.h>
 #include <linux/uaccess.h>
 #include <asm/pgalloc.h>
@@ -168,22 +169,14 @@ bool force_dma_unencrypted(struct device *dev)
 	return is_prot_virt_guest();
 }
 
-#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
-
-int arch_has_restricted_virtio_memory_access(void)
-{
-	return is_prot_virt_guest();
-}
-EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
-
-#endif
-
 /* protected virtualization */
 static void pv_init(void)
 {
 	if (!is_prot_virt_guest())
 		return;
 
+	platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+
 	/* make sure bounce buffers are shared */
 	swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
 	swiotlb_update_mem_attributes();
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 9783ebc4e021..be0b95e51df6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1542,7 +1542,6 @@ config X86_CPA_STATISTICS
 config X86_MEM_ENCRYPT
 	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
 	select DYNAMIC_PHYSICAL_MASK
-	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 	def_bool n
 
 config AMD_MEM_ENCRYPT
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 11350e2fd736..9f27e14e185f 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -12,7 +12,6 @@
 #include <linux/swiotlb.h>
 #include <linux/cc_platform.h>
 #include <linux/mem_encrypt.h>
-#include <linux/virtio_config.h>
 
 /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
 bool force_dma_unencrypted(struct device *dev)
@@ -87,9 +86,3 @@ void __init mem_encrypt_init(void)
 
 	print_mem_encrypt_feature_info();
 }
-
-int arch_has_restricted_virtio_memory_access(void)
-{
-	return cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT);
-}
-EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index e8f7953fda83..f6d038e2cd8e 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -21,6 +21,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/virtio_config.h>
 #include <linux/cc_platform.h>
+#include <linux/platform-feature.h>
 
 #include <asm/tlbflush.h>
 #include <asm/fixmap.h>
@@ -242,6 +243,9 @@ void __init sev_setup_arch(void)
 	size = total_mem * 6 / 100;
 	size = clamp_val(size, IO_TLB_DEFAULT_SIZE, SZ_1G);
 	swiotlb_adjust_size(size);
+
+	/* Set restricted memory access for virtio. */
+	platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
 }
 
 static unsigned long pg_level_to_pfn(int level, pte_t *kpte, pgprot_t *ret_prot)