[PATCH 15/30] KVM: nSVM: save all control fields in svm->nested

From: Paolo Bonzini
Date: Fri May 29 2020 - 11:40:09 EST


In preparation for nested SVM save/restore, store all data that matters
from the VMCB control area into svm->nested. It will then become part
of the nested SVM state that is saved by KVM_SET_NESTED_STATE and
restored by KVM_GET_NESTED_STATE, just like the cached vmcs12 for nVMX.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 73 +++++++++++++++++----------------------
arch/x86/kvm/svm/svm.c | 4 +--
arch/x86/kvm/svm/svm.h | 20 +++--------
3 files changed, 39 insertions(+), 58 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index fd9742c1a860..1e5f460b5540 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -60,7 +60,7 @@ static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index)
{
struct vcpu_svm *svm = to_svm(vcpu);
- u64 cr3 = svm->nested.nested_cr3;
+ u64 cr3 = svm->nested.ctl.nested_cr3;
u64 pdpte;
int ret;

@@ -75,7 +75,7 @@ static unsigned long nested_svm_get_tdp_cr3(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);

- return svm->nested.nested_cr3;
+ return svm->nested.ctl.nested_cr3;
}

static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
@@ -100,8 +100,7 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)

void recalc_intercepts(struct vcpu_svm *svm)
{
- struct vmcb_control_area *c, *h;
- struct nested_state *g;
+ struct vmcb_control_area *c, *h, *g;

mark_dirty(svm->vmcb, VMCB_INTERCEPTS);

@@ -110,7 +109,7 @@ void recalc_intercepts(struct vcpu_svm *svm)

c = &svm->vmcb->control;
h = &svm->nested.hsave->control;
- g = &svm->nested;
+ g = &svm->nested.ctl;

svm->nested.host_intercept_exceptions = h->intercept_exceptions;

@@ -180,7 +179,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
*/
int i;

- if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
+ if (!(svm->nested.ctl.intercept & (1ULL << INTERCEPT_MSR_PROT)))
return true;

for (i = 0; i < MSRPM_OFFSETS; i++) {
@@ -191,7 +190,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
break;

p = msrpm_offsets[i];
- offset = svm->nested.vmcb_msrpm + (p * 4);
+ offset = svm->nested.ctl.msrpm_base_pa + (p * 4);

if (kvm_vcpu_read_guest(&svm->vcpu, offset, &value, 4))
return false;
@@ -229,16 +228,10 @@ static bool nested_vmcb_checks(struct vmcb *vmcb)
static void load_nested_vmcb_control(struct vcpu_svm *svm,
struct vmcb_control_area *control)
{
- svm->nested.nested_cr3 = control->nested_cr3;
+ copy_vmcb_control_area(&svm->nested.ctl, control);

- svm->nested.vmcb_msrpm = control->msrpm_base_pa & ~0x0fffULL;
- svm->nested.vmcb_iopm = control->iopm_base_pa & ~0x0fffULL;
-
- /* cache intercepts */
- svm->nested.intercept_cr = control->intercept_cr;
- svm->nested.intercept_dr = control->intercept_dr;
- svm->nested.intercept_exceptions = control->intercept_exceptions;
- svm->nested.intercept = control->intercept;
+ svm->nested.ctl.msrpm_base_pa &= ~0x0fffULL;
+ svm->nested.ctl.iopm_base_pa &= ~0x0fffULL;
}

static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
@@ -270,34 +263,32 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_v
svm->vmcb->save.cpl = nested_vmcb->save.cpl;
}

-static void nested_prepare_vmcb_control(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
+static void nested_prepare_vmcb_control(struct vcpu_svm *svm)
{
- if (nested_vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE)
+ if (svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_NP_ENABLE)
nested_svm_init_mmu_context(&svm->vcpu);

/* Guest paging mode is active - reset mmu */
kvm_mmu_reset_context(&svm->vcpu);

svm_flush_tlb(&svm->vcpu);
- if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
+ if (svm->nested.ctl.int_ctl & V_INTR_MASKING_MASK)
svm->vcpu.arch.hflags |= HF_VINTR_MASK;
else
svm->vcpu.arch.hflags &= ~HF_VINTR_MASK;

svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset =
- svm->vcpu.arch.l1_tsc_offset + nested_vmcb->control.tsc_offset;
+ svm->vcpu.arch.l1_tsc_offset + svm->nested.ctl.tsc_offset;

- svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
- svm->vmcb->control.virt_ext = nested_vmcb->control.virt_ext;
- svm->vmcb->control.int_vector = nested_vmcb->control.int_vector;
- svm->vmcb->control.int_state = nested_vmcb->control.int_state;
- svm->vmcb->control.event_inj = nested_vmcb->control.event_inj;
- svm->vmcb->control.event_inj_err = nested_vmcb->control.event_inj_err;
+ svm->vmcb->control.int_ctl = svm->nested.ctl.int_ctl | V_INTR_MASKING_MASK;
+ svm->vmcb->control.virt_ext = svm->nested.ctl.virt_ext;
+ svm->vmcb->control.int_vector = svm->nested.ctl.int_vector;
+ svm->vmcb->control.int_state = svm->nested.ctl.int_state;
+ svm->vmcb->control.event_inj = svm->nested.ctl.event_inj;
+ svm->vmcb->control.event_inj_err = svm->nested.ctl.event_inj_err;

- svm->vmcb->control.pause_filter_count =
- nested_vmcb->control.pause_filter_count;
- svm->vmcb->control.pause_filter_thresh =
- nested_vmcb->control.pause_filter_thresh;
+ svm->vmcb->control.pause_filter_count = svm->nested.ctl.pause_filter_count;
+ svm->vmcb->control.pause_filter_thresh = svm->nested.ctl.pause_filter_thresh;

/* Enter Guest-Mode */
enter_guest_mode(&svm->vcpu);
@@ -326,7 +317,7 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,

load_nested_vmcb_control(svm, &nested_vmcb->control);
nested_prepare_vmcb_save(svm, nested_vmcb);
- nested_prepare_vmcb_control(svm, nested_vmcb);
+ nested_prepare_vmcb_control(svm);

/*
* If L1 had a pending IRQ/NMI before executing VMRUN,
@@ -556,7 +547,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
kvm_clear_exception_queue(&svm->vcpu);
kvm_clear_interrupt_queue(&svm->vcpu);

- svm->nested.nested_cr3 = 0;
+ svm->nested.ctl.nested_cr3 = 0;

/* Restore selected save entries */
svm->vmcb->save.es = hsave->save.es;
@@ -606,7 +597,7 @@ static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
u32 offset, msr, value;
int write, mask;

- if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
+ if (!(svm->nested.ctl.intercept & (1ULL << INTERCEPT_MSR_PROT)))
return NESTED_EXIT_HOST;

msr = svm->vcpu.arch.regs[VCPU_REGS_RCX];
@@ -620,7 +611,7 @@ static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
/* Offset is in 32 bit units but need in 8 bit units */
offset *= 4;

- if (kvm_vcpu_read_guest(&svm->vcpu, svm->nested.vmcb_msrpm + offset, &value, 4))
+ if (kvm_vcpu_read_guest(&svm->vcpu, svm->nested.ctl.msrpm_base_pa + offset, &value, 4))
return NESTED_EXIT_DONE;

return (value & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
@@ -633,13 +624,13 @@ static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
u8 start_bit;
u64 gpa;

- if (!(svm->nested.intercept & (1ULL << INTERCEPT_IOIO_PROT)))
+ if (!(svm->nested.ctl.intercept & (1ULL << INTERCEPT_IOIO_PROT)))
return NESTED_EXIT_HOST;

port = svm->vmcb->control.exit_info_1 >> 16;
size = (svm->vmcb->control.exit_info_1 & SVM_IOIO_SIZE_MASK) >>
SVM_IOIO_SIZE_SHIFT;
- gpa = svm->nested.vmcb_iopm + (port / 8);
+ gpa = svm->nested.ctl.iopm_base_pa + (port / 8);
start_bit = port % 8;
iopm_len = (start_bit + size > 8) ? 2 : 1;
mask = (0xf >> (4 - size)) << start_bit;
@@ -665,13 +656,13 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
break;
case SVM_EXIT_READ_CR0 ... SVM_EXIT_WRITE_CR8: {
u32 bit = 1U << (exit_code - SVM_EXIT_READ_CR0);
- if (svm->nested.intercept_cr & bit)
+ if (svm->nested.ctl.intercept_cr & bit)
vmexit = NESTED_EXIT_DONE;
break;
}
case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
u32 bit = 1U << (exit_code - SVM_EXIT_READ_DR0);
- if (svm->nested.intercept_dr & bit)
+ if (svm->nested.ctl.intercept_dr & bit)
vmexit = NESTED_EXIT_DONE;
break;
}
@@ -690,7 +681,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
}
default: {
u64 exit_bits = 1ULL << (exit_code - SVM_EXIT_INTR);
- if (svm->nested.intercept & exit_bits)
+ if (svm->nested.ctl.intercept & exit_bits)
vmexit = NESTED_EXIT_DONE;
}
}
@@ -730,7 +721,7 @@ static bool nested_exit_on_exception(struct vcpu_svm *svm)
{
unsigned int nr = svm->vcpu.arch.exception.nr;

- return (svm->nested.intercept_exceptions & (1 << nr));
+ return (svm->nested.ctl.intercept_exceptions & (1 << nr));
}

static void nested_svm_inject_exception_vmexit(struct vcpu_svm *svm)
@@ -798,7 +789,7 @@ static void nested_svm_intr(struct vcpu_svm *svm)

static inline bool nested_exit_on_init(struct vcpu_svm *svm)
{
- return (svm->nested.intercept & (1ULL << INTERCEPT_INIT));
+ return (svm->nested.ctl.intercept & (1ULL << INTERCEPT_INIT));
}

static void nested_svm_init(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 76b3f553815e..ec98c5979656 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2173,7 +2173,7 @@ static bool check_selective_cr0_intercepted(struct vcpu_svm *svm,
bool ret = false;
u64 intercept;

- intercept = svm->nested.intercept;
+ intercept = svm->nested.ctl.intercept;

if (!is_guest_mode(&svm->vcpu) ||
(!(intercept & (1ULL << INTERCEPT_SELECTIVE_CR0))))
@@ -3649,7 +3649,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
info->intercept == x86_intercept_clts)
break;

- intercept = svm->nested.intercept;
+ intercept = svm->nested.ctl.intercept;

if (!(intercept & (1ULL << INTERCEPT_SELECTIVE_CR0)))
break;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 33e3f09d7a8e..dd5418f20256 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -91,22 +91,12 @@ struct nested_state {
/* These are the merged vectors */
u32 *msrpm;

- /* gpa pointers to the real vectors */
- u64 vmcb_msrpm;
- u64 vmcb_iopm;
-
/* A VMRUN has started but has not yet been performed, so
* we cannot inject a nested vmexit yet. */
bool nested_run_pending;

- /* cache for intercepts of the guest */
- u32 intercept_cr;
- u32 intercept_dr;
- u32 intercept_exceptions;
- u64 intercept;
-
- /* Nested Paging related state */
- u64 nested_cr3;
+ /* cache for control fields of the guest */
+ struct vmcb_control_area ctl;
};

struct vcpu_svm {
@@ -381,17 +371,17 @@ static inline bool svm_nested_virtualize_tpr(struct kvm_vcpu *vcpu)

static inline bool nested_exit_on_smi(struct vcpu_svm *svm)
{
- return (svm->nested.intercept & (1ULL << INTERCEPT_SMI));
+ return (svm->nested.ctl.intercept & (1ULL << INTERCEPT_SMI));
}

static inline bool nested_exit_on_intr(struct vcpu_svm *svm)
{
- return (svm->nested.intercept & (1ULL << INTERCEPT_INTR));
+ return (svm->nested.ctl.intercept & (1ULL << INTERCEPT_INTR));
}

static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
{
- return (svm->nested.intercept & (1ULL << INTERCEPT_NMI));
+ return (svm->nested.ctl.intercept & (1ULL << INTERCEPT_NMI));
}

void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
--
2.26.2