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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2021-03-04 23:40:11 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-03-08 20:41:33 +0100 |
| commit | 229164175ff0c61ff581e6bf37fbfcb608b6e9bb (patch) | |
| tree | 5a321c50675c8cf6ba4349f647ba718b0f92a08b | |
| parent | x86/sev-es: Remove subtraction of res variable (diff) | |
| download | linux-229164175ff0c61ff581e6bf37fbfcb608b6e9bb.tar.xz linux-229164175ff0c61ff581e6bf37fbfcb608b6e9bb.zip | |
x86/virtio: Have SEV guests enforce restricted virtio memory access
An SEV guest requires that virtio devices use the DMA API to allow the
hypervisor to successfully access guest memory as needed.
The VIRTIO_F_VERSION_1 and VIRTIO_F_ACCESS_PLATFORM features tell virtio
to use the DMA API. Add arch_has_restricted_virtio_memory_access() for
x86, to fail the device probe if these features have not been set for the
device when running as an SEV guest.
[ bp: Fix -Wmissing-prototypes warning
Reported-by: kernel test robot <lkp@intel.com> ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/b46e0211f77ca1831f11132f969d470a6ffc9267.1614897610.git.thomas.lendacky@amd.com
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/mm/mem_encrypt.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2792879d398e..e80e7268d2c6 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1518,6 +1518,7 @@ config AMD_MEM_ENCRYPT select ARCH_USE_MEMREMAP_PROT select ARCH_HAS_FORCE_DMA_UNENCRYPTED select INSTRUCTION_DECODER + select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS help Say yes to enable support for the encryption of system memory. This requires an AMD processor that supports Secure Memory diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index 4b01f7dbaf30..f3eb53fe0215 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -19,6 +19,7 @@ #include <linux/kernel.h> #include <linux/bitops.h> #include <linux/dma-mapping.h> +#include <linux/virtio_config.h> #include <asm/tlbflush.h> #include <asm/fixmap.h> @@ -484,3 +485,8 @@ void __init mem_encrypt_init(void) print_mem_encrypt_feature_info(); } +int arch_has_restricted_virtio_memory_access(void) +{ + return sev_active(); +} +EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access); |