[PATCH 0/4] Fix broken SNP support with KVM module built-in

Ashish Kalra
2025-01-22T00:59:45Z

From: Ashish Kalra <ashish.kalra@amd.com>

This patch-set fixes the current SNP host enabling code and effectively SNP
which is broken with respect to the KVM module being built-in.

Essentially SNP host enabling code should be invoked before KVM
initialization, which is currently not the case when KVM is built-in.

SNP host support is enabled in snp_rmptable_init() which is invoked as a
device_initcall(). Here device_initcall() is used as snp_rmptable_init()
expects AMD IOMMU SNP support to be enabled prior to it and the AMD
IOMMU driver enables SNP support after PCI bus enumeration.

The first pre-patch in this patch-set is the AMD IOMMU driver patch
which moves SNP enable check before enabling IOMMUs. With this patch
applied, the final patch in this patch-set calls snp_rmptable_init()
early with subsys_initcall() which then enables SNP host support before
KVM initialization with kvm_amd module built-in. The other two pre-patches
in the patch-set ensure that the dependent PSP SEV driver is initialized
before KVM module if KVM module is built-in.

Fixes: c3b86e61b756 ("x86/cpufeatures: Enable/unmask SEV-SNP CPU feature")

Ashish Kalra (1):
x86/sev: Fix broken SNP support with KVM module built-in

Sean Christopherson (2):
crypto: ccp: Add external API interface for PSP module initialization
KVM: SVM: Ensure PSP module initialized before built-in KVM module

Vasant Hegde (1):
iommu/amd: Check SNP support before enabling IOMMU

arch/x86/kvm/svm/sev.c | 10 ++++++++++
arch/x86/virt/svm/sev.c | 2 +-
drivers/crypto/ccp/sp-dev.c | 12 ++++++++++++
drivers/crypto/ccp/sp-dev.h | 1 +
drivers/iommu/amd/init.c | 3 ++-
include/linux/psp-sev.h | 11 +++++++++++
6 files changed, 37 insertions(+), 2 deletions(-)

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2.34.1