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-rw-r--r--arch/x86/kvm/mmu/mmu.c22
-rw-r--r--arch/x86/kvm/svm/svm.c5
2 files changed, 23 insertions, 4 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6b0576ff2846..c6ed633594a2 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -48,6 +48,7 @@
#include <asm/memtype.h>
#include <asm/cmpxchg.h>
#include <asm/io.h>
+#include <asm/set_memory.h>
#include <asm/vmx.h>
#include <asm/kvm_page_track.h>
#include "trace.h"
@@ -3388,7 +3389,10 @@ static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->lm_root))
return -EIO;
- /* Unlike 32-bit NPT, the PDP table doesn't need to be in low mem. */
+ /*
+ * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and
+ * doesn't need to be decrypted.
+ */
pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
if (!pae_root)
return -ENOMEM;
@@ -5274,6 +5278,8 @@ slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
static void free_mmu_pages(struct kvm_mmu *mmu)
{
+ if (!tdp_enabled && mmu->pae_root)
+ set_memory_encrypted((unsigned long)mmu->pae_root, 1);
free_page((unsigned long)mmu->pae_root);
free_page((unsigned long)mmu->lm_root);
}
@@ -5308,6 +5314,20 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
return -ENOMEM;
mmu->pae_root = page_address(page);
+
+ /*
+ * CR3 is only 32 bits when PAE paging is used, thus it's impossible to
+ * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so
+ * that KVM's writes and the CPU's reads get along. Note, this is
+ * only necessary when using shadow paging, as 64-bit NPT can get at
+ * the C-bit even when shadowing 32-bit NPT, and SME isn't supported
+ * by 32-bit kernels (when KVM itself uses 32-bit NPT).
+ */
+ if (!tdp_enabled)
+ set_memory_decrypted((unsigned long)mmu->pae_root, 1);
+ else
+ WARN_ON_ONCE(shadow_me_mask);
+
for (i = 0; i < 4; ++i)
mmu->pae_root[i] = INVALID_PAE_ROOT;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 58f4dc0e7864..271196400495 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3907,9 +3907,8 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
struct vcpu_svm *svm = to_svm(vcpu);
unsigned long cr3;
- root_hpa = __sme_set(root_hpa);
if (npt_enabled) {
- svm->vmcb->control.nested_cr3 = root_hpa;
+ svm->vmcb->control.nested_cr3 = __sme_set(root_hpa);
vmcb_mark_dirty(svm->vmcb, VMCB_NPT);
/* Loading L2's CR3 is handled by enter_svm_guest_mode. */
@@ -3917,7 +3916,7 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
return;
cr3 = vcpu->arch.cr3;
} else if (vcpu->arch.mmu->shadow_root_level >= PT64_ROOT_4LEVEL) {
- cr3 = root_hpa | kvm_get_active_pcid(vcpu);
+ cr3 = __sme_set(root_hpa) | kvm_get_active_pcid(vcpu);
} else {
/* PCID in the guest should be impossible with a 32-bit MMU. */
WARN_ON_ONCE(kvm_get_active_pcid(vcpu));