[PATCH v4 7/7] nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in struct svm_nested_state

Emanuele Giuseppe Esposito
2021-11-03T11:53:51Z

This requires changing all vmcb_is_intercept(&svm->nested.ctl, ...)
calls with vmcb12_is_intercept().

In addition, in svm_get_nested_state() user space expects a
vmcb_control_area struct, so we need to copy back all fields
in a temporary structure to provide to the user space.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
arch/x86/kvm/svm/nested.c | 48 +++++++++++++++++++++++++--------------
arch/x86/kvm/svm/svm.c | 4 ++--
arch/x86/kvm/svm/svm.h | 8 +++----
3 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 7895ddf176ed..27d0871de854 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -58,8 +58,9 @@ static void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_excep
struct vcpu_svm *svm = to_svm(vcpu);
WARN_ON(!is_guest_mode(vcpu));

- if (vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) &&
- !svm->nested.nested_run_pending) {
+ if (vmcb12_is_intercept(&svm->nested.ctl,
+ INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) &&
+ !svm->nested.nested_run_pending) {
svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR;
svm->vmcb->control.exit_code_hi = 0;
svm->vmcb->control.exit_info_1 = fault->error_code;
@@ -121,7 +122,8 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)

void recalc_intercepts(struct vcpu_svm *svm)
{
- struct vmcb_control_area *c, *h, *g;
+ struct vmcb_control_area *c, *h;
+ struct vmcb_ctrl_area_cached *g;
unsigned int i;

vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
@@ -172,7 +174,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
*/
int i;

- if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
+ if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
return true;

for (i = 0; i < MSRPM_OFFSETS; i++) {
@@ -208,9 +210,9 @@ static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size)
}

static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
- struct vmcb_control_area *control)
+ struct vmcb_ctrl_area_cached *control)
{
- if (CC(!vmcb_is_intercept(control, INTERCEPT_VMRUN)))
+ if (CC(!vmcb12_is_intercept(control, INTERCEPT_VMRUN)))
return false;

if (CC(control->asid == 0))
@@ -273,7 +275,7 @@ static bool nested_vmcb_check_save(struct kvm_vcpu *vcpu)
}

static
-void _nested_copy_vmcb_control_to_cache(struct vmcb_control_area *to,
+void _nested_copy_vmcb_control_to_cache(struct vmcb_ctrl_area_cached *to,
struct vmcb_control_area *from)
{
unsigned int i;
@@ -976,7 +978,7 @@ static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
u32 offset, msr, value;
int write, mask;

- if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
+ if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
return NESTED_EXIT_HOST;

msr = svm->vcpu.arch.regs[VCPU_REGS_RCX];
@@ -1003,7 +1005,7 @@ static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
u8 start_bit;
u64 gpa;

- if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT)))
+ if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT)))
return NESTED_EXIT_HOST;

port = svm->vmcb->control.exit_info_1 >> 16;
@@ -1034,12 +1036,12 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
vmexit = nested_svm_intercept_ioio(svm);
break;
case SVM_EXIT_READ_CR0 ... SVM_EXIT_WRITE_CR8: {
- if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+ if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
vmexit = NESTED_EXIT_DONE;
break;
}
case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
- if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+ if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
vmexit = NESTED_EXIT_DONE;
break;
}
@@ -1057,7 +1059,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
break;
}
default: {
- if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+ if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
vmexit = NESTED_EXIT_DONE;
}
}
@@ -1135,7 +1137,7 @@ static void nested_svm_inject_exception_vmexit(struct vcpu_svm *svm)

static inline bool nested_exit_on_init(struct vcpu_svm *svm)
{
- return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INIT);
+ return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INIT);
}

static int svm_check_nested_events(struct kvm_vcpu *vcpu)
@@ -1268,6 +1270,8 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu,
u32 user_data_size)
{
struct vcpu_svm *svm;
+ struct vmcb_control_area *ctl;
+ unsigned long r;
struct kvm_nested_state kvm_state = {
.flags = 0,
.format = KVM_STATE_NESTED_FORMAT_SVM,
@@ -1309,9 +1313,18 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu,
*/
if (clear_user(user_vmcb, KVM_STATE_NESTED_SVM_VMCB_SIZE))
return -EFAULT;
- if (copy_to_user(&user_vmcb->control, &svm->nested.ctl,
- sizeof(user_vmcb->control)))
+
+ ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+ if (!ctl)
+ return -ENOMEM;
+
+ nested_copy_vmcb_cache_to_control(ctl, &svm->nested.ctl);
+ r = copy_to_user(&user_vmcb->control, ctl,
+ sizeof(user_vmcb->control));
+ kfree(ctl);
+ if (r)
return -EFAULT;
+
if (copy_to_user(&user_vmcb->save, &svm->vmcb01.ptr->save,
sizeof(user_vmcb->save)))
return -EFAULT;
@@ -1329,6 +1342,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
struct vmcb_control_area *ctl;
struct vmcb_save_area *save;
struct vmcb_save_area_cached save_cached;
+ struct vmcb_ctrl_area_cached ctl_cached;
unsigned long cr0;
int ret;

@@ -1381,7 +1395,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
goto out_free;

ret = -EINVAL;
- if (!nested_vmcb_check_controls(vcpu, ctl))
+ _nested_copy_vmcb_control_to_cache(&ctl_cached, ctl);
+ if (!nested_vmcb_check_controls(vcpu, &ctl_cached))
goto out_free;

/*
@@ -1438,7 +1453,6 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
svm->nested.vmcb12_gpa = kvm_state->hdr.svm.vmcb_pa;

svm_copy_vmrun_state(&svm->vmcb01.ptr->save, save);
- nested_copy_vmcb_control_to_cache(svm, ctl);

svm_switch_vmcb(svm, &svm->nested.vmcb02);
nested_vmcb02_prepare_control(svm);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4e586ce77591..86d966802bbc 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2440,7 +2440,7 @@ static bool check_selective_cr0_intercepted(struct kvm_vcpu *vcpu,
bool ret = false;

if (!is_guest_mode(vcpu) ||
- (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0))))
+ (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0))))
return false;

cr0 &= ~SVM_CR0_SELECTIVE_MASK;
@@ -4158,7 +4158,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
info->intercept == x86_intercept_clts)
break;

- if (!(vmcb_is_intercept(&svm->nested.ctl,
+ if (!(vmcb12_is_intercept(&svm->nested.ctl,
INTERCEPT_SELECTIVE_CR0)))
break;

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 49cc502986a9..5d1cdf90aa55 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -156,7 +156,7 @@ struct svm_nested_state {
bool nested_run_pending;

/* cache for control fields of the guest */
- struct vmcb_control_area ctl;
+ struct vmcb_ctrl_area_cached ctl;
struct vmcb_save_area_cached save;

bool initialized;
@@ -491,17 +491,17 @@ static inline bool nested_svm_virtualize_tpr(struct kvm_vcpu *vcpu)

static inline bool nested_exit_on_smi(struct vcpu_svm *svm)
{
- return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_SMI);
+ return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SMI);
}

static inline bool nested_exit_on_intr(struct vcpu_svm *svm)
{
- return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_INTR);
+ return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INTR);
}

static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
{
- return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_NMI);
+ return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_NMI);
}

int enter_svm_guest_mode(struct kvm_vcpu *vcpu,
--
2.27.0