From: Ashish Kalra <ashish.kalra@xxxxxxx> Implement a workaround for an SNP erratum where the CPU will incorrectly signal an RMP violation #PF if a hugepage (2mb or 1gb) collides with the RMP entry of the VMSAVE target page. When SEV-SNP is globally enabled, the CPU marks the VMSAVE target page as "InUse" while the VMSAVE instruction is executing. If another CPU writes to a different page in the same 2MB region while the VMSAVE is executing, the CPU will throw an RMP violation #PF. Use the snp safe generic allocator for allocating the VMSA target page which will ensure that the page returned is not a hugepage, as it is already being used for the allocating the VMCB, VMSA and AVIC backing page. Co-developed-by: Marc Orr <marcorr@xxxxxxxxxx> Signed-off-by: Marc Orr <marcorr@xxxxxxxxxx> Reported-by: Alper Gun <alpergun@xxxxxxxxxx> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> Signed-off-by: Michael Roth <michael.roth@xxxxxxx> --- arch/x86/kvm/svm/svm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 543261c87eb3..1d4a723d5def 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -653,7 +653,7 @@ static int svm_cpu_init(int cpu) int ret = -ENOMEM; memset(sd, 0, sizeof(struct svm_cpu_data)); - sd->save_area = alloc_page(GFP_KERNEL | __GFP_ZERO); + sd->save_area = snp_safe_alloc_page(NULL); if (!sd->save_area) return ret; -- 2.25.1
