Commit cc440cda authored by Paolo Bonzini's avatar Paolo Bonzini

KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE

Similar to VMX, the state that is captured through the currently available
IOCTLs is a mix of L1 and L2 state, dependent on whether the L2 guest was
running at the moment when the process was interrupted to save its state.

In particular, the SVM-specific state for nested virtualization includes
the L1 saved state (including the interrupt flag), the cached L2 controls,
and the GIF.
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8ec107c8
......@@ -385,18 +385,22 @@ struct kvm_sync_regs {
#define KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT (1 << 4)
#define KVM_STATE_NESTED_FORMAT_VMX 0
#define KVM_STATE_NESTED_FORMAT_SVM 1 /* unused */
#define KVM_STATE_NESTED_FORMAT_SVM 1
#define KVM_STATE_NESTED_GUEST_MODE 0x00000001
#define KVM_STATE_NESTED_RUN_PENDING 0x00000002
#define KVM_STATE_NESTED_EVMCS 0x00000004
#define KVM_STATE_NESTED_MTF_PENDING 0x00000008
#define KVM_STATE_NESTED_GIF_SET 0x00000100
#define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001
#define KVM_STATE_NESTED_SMM_VMXON 0x00000002
#define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000
#define KVM_STATE_NESTED_SVM_VMCB_SIZE 0x1000
struct kvm_vmx_nested_state_data {
__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
......@@ -411,6 +415,15 @@ struct kvm_vmx_nested_state_hdr {
} smm;
};
struct kvm_svm_nested_state_data {
/* Save area only used if KVM_STATE_NESTED_RUN_PENDING. */
__u8 vmcb12[KVM_STATE_NESTED_SVM_VMCB_SIZE];
};
struct kvm_svm_nested_state_hdr {
__u64 vmcb_pa;
};
/* for KVM_CAP_NESTED_STATE */
struct kvm_nested_state {
__u16 flags;
......@@ -419,6 +432,7 @@ struct kvm_nested_state {
union {
struct kvm_vmx_nested_state_hdr vmx;
struct kvm_svm_nested_state_hdr svm;
/* Pad the header to 128 bytes. */
__u8 pad[120];
......@@ -431,6 +445,7 @@ struct kvm_nested_state {
*/
union {
struct kvm_vmx_nested_state_data vmx[0];
struct kvm_svm_nested_state_data svm[0];
} data;
};
......
......@@ -303,4 +303,9 @@ static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature)
kvm_cpu_cap_set(x86_feature);
}
static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
{
return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
}
#endif
......@@ -25,6 +25,7 @@
#include "trace.h"
#include "mmu.h"
#include "x86.h"
#include "cpuid.h"
#include "lapic.h"
#include "svm.h"
......@@ -238,6 +239,8 @@ static void load_nested_vmcb_control(struct vcpu_svm *svm,
{
copy_vmcb_control_area(&svm->nested.ctl, control);
/* Copy it here because nested_svm_check_controls will check it. */
svm->nested.ctl.asid = control->asid;
svm->nested.ctl.msrpm_base_pa &= ~0x0fffULL;
svm->nested.ctl.iopm_base_pa &= ~0x0fffULL;
}
......@@ -930,6 +933,150 @@ int nested_svm_exit_special(struct vcpu_svm *svm)
return NESTED_EXIT_CONTINUE;
}
static int svm_get_nested_state(struct kvm_vcpu *vcpu,
struct kvm_nested_state __user *user_kvm_nested_state,
u32 user_data_size)
{
struct vcpu_svm *svm;
struct kvm_nested_state kvm_state = {
.flags = 0,
.format = KVM_STATE_NESTED_FORMAT_SVM,
.size = sizeof(kvm_state),
};
struct vmcb __user *user_vmcb = (struct vmcb __user *)
&user_kvm_nested_state->data.svm[0];
if (!vcpu)
return kvm_state.size + KVM_STATE_NESTED_SVM_VMCB_SIZE;
svm = to_svm(vcpu);
if (user_data_size < kvm_state.size)
goto out;
/* First fill in the header and copy it out. */
if (is_guest_mode(vcpu)) {
kvm_state.hdr.svm.vmcb_pa = svm->nested.vmcb;
kvm_state.size += KVM_STATE_NESTED_SVM_VMCB_SIZE;
kvm_state.flags |= KVM_STATE_NESTED_GUEST_MODE;
if (svm->nested.nested_run_pending)
kvm_state.flags |= KVM_STATE_NESTED_RUN_PENDING;
}
if (gif_set(svm))
kvm_state.flags |= KVM_STATE_NESTED_GIF_SET;
if (copy_to_user(user_kvm_nested_state, &kvm_state, sizeof(kvm_state)))
return -EFAULT;
if (!is_guest_mode(vcpu))
goto out;
/*
* Copy over the full size of the VMCB rather than just the size
* of the structs.
*/
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)))
return -EFAULT;
if (copy_to_user(&user_vmcb->save, &svm->nested.hsave->save,
sizeof(user_vmcb->save)))
return -EFAULT;
out:
return kvm_state.size;
}
static int svm_set_nested_state(struct kvm_vcpu *vcpu,
struct kvm_nested_state __user *user_kvm_nested_state,
struct kvm_nested_state *kvm_state)
{
struct vcpu_svm *svm = to_svm(vcpu);
struct vmcb *hsave = svm->nested.hsave;
struct vmcb __user *user_vmcb = (struct vmcb __user *)
&user_kvm_nested_state->data.svm[0];
struct vmcb_control_area ctl;
struct vmcb_save_area save;
u32 cr0;
if (kvm_state->format != KVM_STATE_NESTED_FORMAT_SVM)
return -EINVAL;
if (kvm_state->flags & ~(KVM_STATE_NESTED_GUEST_MODE |
KVM_STATE_NESTED_RUN_PENDING |
KVM_STATE_NESTED_GIF_SET))
return -EINVAL;
/*
* If in guest mode, vcpu->arch.efer actually refers to the L2 guest's
* EFER.SVME, but EFER.SVME still has to be 1 for VMRUN to succeed.
*/
if (!(vcpu->arch.efer & EFER_SVME)) {
/* GIF=1 and no guest mode are required if SVME=0. */
if (kvm_state->flags != KVM_STATE_NESTED_GIF_SET)
return -EINVAL;
}
/* SMM temporarily disables SVM, so we cannot be in guest mode. */
if (is_smm(vcpu) && (kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
return -EINVAL;
if (!(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE)) {
svm_leave_nested(svm);
goto out_set_gif;
}
if (!page_address_valid(vcpu, kvm_state->hdr.svm.vmcb_pa))
return -EINVAL;
if (kvm_state->size < sizeof(*kvm_state) + KVM_STATE_NESTED_SVM_VMCB_SIZE)
return -EINVAL;
if (copy_from_user(&ctl, &user_vmcb->control, sizeof(ctl)))
return -EFAULT;
if (copy_from_user(&save, &user_vmcb->save, sizeof(save)))
return -EFAULT;
if (!nested_vmcb_check_controls(&ctl))
return -EINVAL;
/*
* Processor state contains L2 state. Check that it is
* valid for guest mode (see nested_vmcb_checks).
*/
cr0 = kvm_read_cr0(vcpu);
if (((cr0 & X86_CR0_CD) == 0) && (cr0 & X86_CR0_NW))
return -EINVAL;
/*
* Validate host state saved from before VMRUN (see
* nested_svm_check_permissions).
* TODO: validate reserved bits for all saved state.
*/
if (!(save.cr0 & X86_CR0_PG))
return -EINVAL;
/*
* All checks done, we can enter guest mode. L1 control fields
* come from the nested save state. Guest state is already
* in the registers, the save area of the nested state instead
* contains saved L1 state.
*/
copy_vmcb_control_area(&hsave->control, &svm->vmcb->control);
hsave->save = save;
svm->nested.vmcb = kvm_state->hdr.svm.vmcb_pa;
load_nested_vmcb_control(svm, &ctl);
nested_prepare_vmcb_control(svm);
out_set_gif:
svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));
return 0;
}
struct kvm_x86_nested_ops svm_nested_ops = {
.check_events = svm_check_nested_events,
.get_state = svm_get_nested_state,
.set_state = svm_set_nested_state,
};
......@@ -1193,6 +1193,7 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu)
svm->avic_is_running = true;
svm->nested.hsave = page_address(hsave_page);
clear_page(svm->nested.hsave);
svm->msrpm = page_address(msrpm_pages);
svm_vcpu_init_msrpm(svm->msrpm);
......
......@@ -437,11 +437,6 @@ static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
}
}
static bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
{
return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
}
static int nested_vmx_check_io_bitmap_controls(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12)
{
......
......@@ -4628,7 +4628,8 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
if (kvm_state.flags &
~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE
| KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_MTF_PENDING))
| KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_MTF_PENDING
| KVM_STATE_NESTED_GIF_SET))
break;
/* nested_run_pending implies guest_mode. */
......
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