The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 985e537a4082b4635754a57f4f95430790afee6a Gitweb: https://git.kernel.org/tip/985e537a4082b4635754a57f4f95430790afee6a Author: Tom Lendacky thomas.lendacky@amd.com AuthorDate: Tue, 10 Mar 2020 18:35:57 +01:00 Committer: Borislav Petkov bp@suse.de CommitterDate: Wed, 11 Mar 2020 15:54:54 +01:00

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/2d9e16eb5b53dc82665c95c6764b7407719df7a0.158264532... --- arch/x86/mm/ioremap.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 44e4beb..935a91e 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); }

/*