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| author |   Tom Lendacky <thomas.lendacky@amd.com> | 2020-03-10 18:35:57 +0100 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2020-03-11 15:54:54 +0100 |
| commit | 985e537a4082b4635754a57f4f95430790afee6a (patch) | |
| tree | 506b1454c4c6401263bf250598a4a2fca8edf188 /arch/x86 | |
| parent | Linux 5.6-rc5 (diff) | |
| download | linux-dev-985e537a4082b4635754a57f4f95430790afee6a.tar.xz linux-dev-985e537a4082b4635754a57f4f95430790afee6a.zip | |
x86/ioremap: Map EFI runtime services data as encrypted for SEV
The dmidecode program fails to properly decode the SMBIOS data supplied
by OVMF/UEFI when running in an SEV guest. The SMBIOS area, under SEV, is
encrypted and resides in reserved memory that is marked as EFI runtime
services data.
As a result, when memremap() is attempted for the SMBIOS data, it
can't be mapped as regular RAM (through try_ram_remap()) and, since
the address isn't part of the iomem resources list, it isn't mapped
encrypted through the fallback ioremap().
Add a new __ioremap_check_other() to deal with memory types like
EFI_RUNTIME_SERVICES_DATA which are not covered by the resource ranges.
This allows any runtime services data which has been created encrypted,
to be mapped encrypted too.
[ bp: Move functionality to a separate function. ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Joerg Roedel <jroedel@suse.de>
Cc: <stable@vger.kernel.org> # 5.3
Link: https://lkml.kernel.org/r/2d9e16eb5b53dc82665c95c6764b7407719df7a0.1582645327.git.thomas.lendacky@amd.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/mm/ioremap.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 44e4beb4239f..935a91e1fd77 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -106,6 +106,19 @@ static unsigned int __ioremap_check_encrypted(struct resource *res) return 0; } +/* + * The EFI runtime services data area is not covered by walk_mem_res(), but must + * be mapped encrypted when SEV is active. + */ +static void __ioremap_check_other(resource_size_t addr, struct ioremap_desc *desc) +{ + if (!sev_active()) + return; + + if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA) + desc->flags |= IORES_MAP_ENCRYPTED; +} + static int __ioremap_collect_map_flags(struct resource *res, void *arg) { struct ioremap_desc *desc = arg; @@ -124,6 +137,9 @@ static int __ioremap_collect_map_flags(struct resource *res, void *arg) * To avoid multiple resource walks, this function walks resources marked as * IORESOURCE_MEM and IORESOURCE_BUSY and looking for system RAM and/or a * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES). + * + * After that, deal with misc other ranges in __ioremap_check_other() which do + * not fall into the above category. */ static void __ioremap_check_mem(resource_size_t addr, unsigned long size, struct ioremap_desc *desc) @@ -135,6 +151,8 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size, memset(desc, 0, sizeof(struct ioremap_desc)); walk_mem_res(start, end, desc, __ioremap_collect_map_flags); + + __ioremap_check_other(addr, desc); } /* |