diff options
author | Michael Roth <michael.roth@amd.com> | 2021-12-16 20:13:54 +0300 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-01-07 18:44:46 +0300 |
commit | 405329fc9aeef1e3e2eccaadf32b539ad6c7120f (patch) | |
tree | dd8be0f01d94130ad82ea54e3dd6b51808c796e8 /arch/x86 | |
parent | 907d139318b5109e5b676b32b0f4a2c666a8d9ac (diff) | |
download | linux-405329fc9aeef1e3e2eccaadf32b539ad6c7120f.tar.xz |
KVM: SVM: include CR3 in initial VMSA state for SEV-ES guests
Normally guests will set up CR3 themselves, but some guests, such as
kselftests, and potentially CONFIG_PVH guests, rely on being booted
with paging enabled and CR3 initialized to a pre-allocated page table.
Currently CR3 updates via KVM_SET_SREGS* are not loaded into the guest
VMCB until just prior to entering the guest. For SEV-ES/SEV-SNP, this
is too late, since it will have switched over to using the VMSA page
prior to that point, with the VMSA CR3 copied from the VMCB initial
CR3 value: 0.
Address this by sync'ing the CR3 value into the VMCB save area
immediately when KVM_SET_SREGS* is issued so it will find it's way into
the initial VMSA.
Suggested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-Id: <20211216171358.61140-10-michael.roth@amd.com>
[Remove vmx_post_set_cr3; add a remark about kvm_set_cr3 not calling the
new hook. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/include/asm/kvm-x86-ops.h | 1 | ||||
-rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
-rw-r--r-- | arch/x86/kvm/svm/svm.c | 19 | ||||
-rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 1 | ||||
-rw-r--r-- | arch/x86/kvm/x86.c | 2 |
5 files changed, 24 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 9e50da3ed01a..f658bb4dbb74 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -35,6 +35,7 @@ KVM_X86_OP(get_cpl) KVM_X86_OP(set_segment) KVM_X86_OP_NULL(get_cs_db_l_bits) KVM_X86_OP(set_cr0) +KVM_X86_OP_NULL(post_set_cr3) KVM_X86_OP(is_valid_cr4) KVM_X86_OP(set_cr4) KVM_X86_OP(set_efer) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 623fb7c4992c..6cbf97a2ebc4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1344,6 +1344,7 @@ struct kvm_x86_ops { struct kvm_segment *var, int seg); void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l); void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0); + void (*post_set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3); bool (*is_valid_cr4)(struct kvm_vcpu *vcpu, unsigned long cr0); void (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4); int (*set_efer)(struct kvm_vcpu *vcpu, u64 efer); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 5557867dcb69..c3d9006478a4 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1801,6 +1801,24 @@ static void svm_set_gdt(struct kvm_vcpu *vcpu, struct desc_ptr *dt) vmcb_mark_dirty(svm->vmcb, VMCB_DT); } +static void svm_post_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + /* + * For guests that don't set guest_state_protected, the cr3 update is + * handled via kvm_mmu_load() while entering the guest. For guests + * that do (SEV-ES/SEV-SNP), the cr3 update needs to be written to + * VMCB save area now, since the save area will become the initial + * contents of the VMSA, and future VMCB save area updates won't be + * seen. + */ + if (sev_es_guest(vcpu->kvm)) { + svm->vmcb->save.cr3 = cr3; + vmcb_mark_dirty(svm->vmcb, VMCB_CR); + } +} + void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { struct vcpu_svm *svm = to_svm(vcpu); @@ -4624,6 +4642,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .get_cpl = svm_get_cpl, .get_cs_db_l_bits = kvm_get_cs_db_l_bits, .set_cr0 = svm_set_cr0, + .post_set_cr3 = svm_post_set_cr3, .is_valid_cr4 = svm_is_valid_cr4, .set_cr4 = svm_set_cr4, .set_efer = svm_set_efer, diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1d53b8144f83..7b5abe25e1e5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3134,6 +3134,7 @@ static void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, vmcs_writel(GUEST_CR3, guest_cr3); } + static bool vmx_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) { /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6492329f2e9a..a9f1044dd6b2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1179,6 +1179,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) vcpu->arch.cr3 = cr3; kvm_register_mark_dirty(vcpu, VCPU_EXREG_CR3); + /* Do not call post_set_cr3, we do not get here for confidential guests. */ handle_tlb_flush: /* @@ -10618,6 +10619,7 @@ static int __set_sregs_common(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs, *mmu_reset_needed |= kvm_read_cr3(vcpu) != sregs->cr3; vcpu->arch.cr3 = sregs->cr3; kvm_register_mark_dirty(vcpu, VCPU_EXREG_CR3); + static_call_cond(kvm_x86_post_set_cr3)(vcpu, sregs->cr3); kvm_set_cr8(vcpu, sregs->cr8); |