This patch series enables SNP-host support when running on Hyper-V, which allows launching SNP guests while running as a nested hypervisor. This works with SNP guest side support that was merged in v5.19, and the snp capable qemu from AMD. In this scenario the L0 hypervisor is Hyper-V, L1 is KVM, and L2 is an SNP guest. The code from this patchset runs in L1. L1 is not an SNP guest itself, SNP guests are not capable of supporting virtualization. Patch 1 deals with allocating an RMP table which is not provided by firmware/hypervisor, but is needed by the kernel to keep track of page assignment to guests and rmp page size. Patch 2 implements MSR-based rmpupdate/psmash instructions which are meant for virtualized environments. Patch 3 containts the logic to update the rmp table when rmpupdate/psmash is issued. Patch 4 makes sure that the kernel does not disable SNP support during early CPU init. Patch 5 allows SNP initialization to proceed when no iommus are available. Patch 6 adds a quirk in psp command buffer handling, because of differences in SNP firmware spec interpretation. Patch 7 adds handling for RMP faults which occur as NPF and the L0 is not able to resolve the address that the fault occurred at. This series depends on: - "Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support" (applies on top of RFC v7) https://lore.kernel.org/lkml/20221214194056.161492-1-michael.roth@xxxxxxx/ - "Support ACPI PSP on Hyper-V" https://lore.kernel.org/lkml/20230213092429.1167812-1-jpiotrowski@xxxxxxxxxxxxxxxxxxx/ Changes since v1: * added handling for rmp page faults that occur during copy_to_user() that don't come with a proper fault address when running nested. * fold IS_ENABLED() test into hv_needs_snp_rmp(), and use CONFIG_KVM_AMD_SEV instead of CONFIG_AMD_MEM_ENCRYPT * introduce snp_soft_rmptable() wrapper to remove core dependency on hyperv specific code * use msr_set_bit for SYSCFG_MEM_ENCRYPT bit instead of open coding Jeremi Piotrowski (7): x86/hyperv: Allocate RMP table during boot x86/sev: Add support for NestedVirtSnpMsr x86/sev: Maintain shadow rmptable on Hyper-V x86/amd: Configure necessary MSRs for SNP during CPU init when running as a guest iommu/amd: Don't fail snp_enable when running virtualized crypto: ccp - Introduce quirk to always reclaim pages after SEV-legacy commands x86/fault: Handle RMP faults with 0 address when nested arch/x86/hyperv/hv_init.c | 5 + arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/hyperv-tlfs.h | 3 + arch/x86/include/asm/mshyperv.h | 3 + arch/x86/include/asm/msr-index.h | 2 + arch/x86/include/asm/sev.h | 6 ++ arch/x86/kernel/cpu/amd.c | 5 +- arch/x86/kernel/cpu/mshyperv.c | 47 +++++++++ arch/x86/kernel/sev.c | 150 ++++++++++++++++++++++++++--- arch/x86/mm/fault.c | 14 +++ drivers/crypto/ccp/sev-dev.c | 6 +- drivers/crypto/ccp/sp-dev.h | 4 + drivers/crypto/ccp/sp-platform.c | 1 + drivers/iommu/amd/init.c | 6 ++ 14 files changed, 240 insertions(+), 13 deletions(-) -- 2.25.1
