[RFC PATCH 2/2] nSVM: use vmcb_ctrl_area_cached instead of vmcb_control_area in svm_nested_state
From: Emanuele Giuseppe Esposito
Date: Fri Sep 17 2021 - 08:50:51 EST
This requires changing all vmcb_is_intercept(&svm->nested.ctl, ...)
calls with vmcb_is_intercept_cached().
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@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 42 ++++++++++++++++++++++-----------------
arch/x86/kvm/svm/svm.c | 4 ++--
arch/x86/kvm/svm/svm.h | 8 ++++----
3 files changed, 30 insertions(+), 24 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index d06a95156535..1f8c90cc4fc3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -58,8 +58,8 @@ 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 (vmcb_is_intercept_cached(&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 +121,8 @@ 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);
@@ -163,7 +164,7 @@ void recalc_intercepts(struct vcpu_svm *svm)
vmcb_set_intercept(c, INTERCEPT_VMSAVE);
}
-static void copy_vmcb_control_area(struct vmcb_control_area *dst,
+static void copy_vmcb_control_area(struct vmcb_ctrl_area_cached *dst,
struct vmcb_control_area *from)
{
unsigned int i;
@@ -219,7 +220,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
*/
int i;
- if (!(vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
+ if (!(vmcb_is_intercept_cached(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
return true;
for (i = 0; i < MSRPM_OFFSETS; i++) {
@@ -255,9 +256,9 @@ 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(!vmcb_is_intercept_cached(control, INTERCEPT_VMRUN)))
return false;
if (CC(control->asid == 0))
@@ -971,7 +972,7 @@ 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 (!(vmcb_is_intercept_cached(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
return NESTED_EXIT_HOST;
msr = svm->vcpu.arch.regs[VCPU_REGS_RCX];
@@ -998,7 +999,7 @@ 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 (!(vmcb_is_intercept_cached(&svm->nested.ctl, INTERCEPT_IOIO_PROT)))
return NESTED_EXIT_HOST;
port = svm->vmcb->control.exit_info_1 >> 16;
@@ -1029,12 +1030,12 @@ 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 (vmcb_is_intercept_cached(&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 (vmcb_is_intercept_cached(&svm->nested.ctl, exit_code))
vmexit = NESTED_EXIT_DONE;
break;
}
@@ -1052,7 +1053,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
break;
}
default: {
- if (vmcb_is_intercept(&svm->nested.ctl, exit_code))
+ if (vmcb_is_intercept_cached(&svm->nested.ctl, exit_code))
vmexit = NESTED_EXIT_DONE;
}
}
@@ -1130,7 +1131,7 @@ 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 vmcb_is_intercept_cached(&svm->nested.ctl, INTERCEPT_INIT);
}
static int svm_check_nested_events(struct kvm_vcpu *vcpu)
@@ -1261,6 +1262,7 @@ static int svm_get_nested_state(struct kvm_vcpu *vcpu,
u32 user_data_size)
{
struct vcpu_svm *svm;
+ struct vmcb_control_area ctl_temp;
struct kvm_nested_state kvm_state = {
.flags = 0,
.format = KVM_STATE_NESTED_FORMAT_SVM,
@@ -1302,7 +1304,8 @@ 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,
+ copy_vmcb_ctrl_area_cached(&ctl_temp, &svm->nested.ctl);
+ if (copy_to_user(&user_vmcb->control, &ctl_temp,
sizeof(user_vmcb->control)))
return -EFAULT;
if (copy_to_user(&user_vmcb->save, &svm->vmcb01.ptr->save,
@@ -1373,8 +1376,9 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
goto out_free;
ret = -EINVAL;
- if (!nested_vmcb_check_controls(vcpu, ctl))
- goto out_free;
+ nested_load_control_from_vmcb12(svm, ctl);
+ if (!nested_vmcb_check_controls(vcpu, &svm->nested.ctl))
+ goto out_free_ctl;
/*
* Processor state contains L2 state. Check that it is
@@ -1382,7 +1386,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
*/
cr0 = kvm_read_cr0(vcpu);
if (((cr0 & X86_CR0_CD) == 0) && (cr0 & X86_CR0_NW))
- goto out_free;
+ goto out_free_ctl;
/*
* Validate host state saved from before VMRUN (see
@@ -1428,7 +1432,6 @@ 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_load_control_from_vmcb12(svm, ctl);
svm_switch_vmcb(svm, &svm->nested.vmcb02);
nested_vmcb02_prepare_control(svm);
@@ -1438,6 +1441,9 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
out_free_save:
memset(&svm->nested.save, 0, sizeof(struct vmcb_save_area_cached));
+out_free_ctl:
+ memset(&svm->nested.ctl, 0, sizeof(struct vmcb_ctrl_area_cached));
+
out_free:
kfree(save);
kfree(ctl);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 169b930322ef..5ec4f56b3b09 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2465,7 +2465,7 @@ 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))))
+ (!(vmcb_is_intercept_cached(&svm->nested.ctl, INTERCEPT_SELECTIVE_CR0))))
return false;
cr0 &= ~SVM_CR0_SELECTIVE_MASK;
@@ -4184,7 +4184,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
info->intercept == x86_intercept_clts)
break;
- if (!(vmcb_is_intercept(&svm->nested.ctl,
+ if (!(vmcb_is_intercept_cached(&svm->nested.ctl,
INTERCEPT_SELECTIVE_CR0)))
break;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a00be2516cc6..69dbce80b4b8 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -152,7 +152,7 @@ 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;
@@ -487,17 +487,17 @@ 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 vmcb_is_intercept_cached(&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 vmcb_is_intercept_cached(&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 vmcb_is_intercept_cached(&svm->nested.ctl, INTERCEPT_NMI);
}
int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb_gpa, struct vmcb *vmcb12);
--
2.27.0