Re: [PATCH v2 036/144] KVM: selftest: Add proper helpers for x86-specific save/restore ioctls

Wang, Lei
2022-11-23T02:27:10Z

On 6/3/2022 8:41 AM, Sean Christopherson wrote:
> Add helpers for the various one-off helpers used by x86's vCPU state
> save/restore helpers, and convert the other open coded ioctl()s to use
> existing helpers.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> .../selftests/kvm/include/x86_64/processor.h | 54 ++++++++
> .../selftests/kvm/lib/x86_64/processor.c | 126 +++++-------------
> 2 files changed, 91 insertions(+), 89 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index e4268432cfe8..1d46d60bb480 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -432,6 +432,60 @@ const struct kvm_msr_list *kvm_get_feature_msr_index_list(void);
> bool kvm_msr_is_in_save_restore_list(uint32_t msr_index);
> uint64_t kvm_get_feature_msr(uint64_t msr_index);
>
> +static inline void vcpu_msrs_get(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_msrs *msrs)
> +{
> + int r = __vcpu_ioctl(vm, vcpuid, KVM_GET_MSRS, msrs);
> +
> + TEST_ASSERT(r == msrs->nmsrs,
> + "KVM_GET_MSRS failed, r: %i (failed on MSR %x)",
> + r, r < 0 || r >= msrs->nmsrs ? -1 : msrs->entries[r].index);
> +}
> +static inline void vcpu_msrs_set(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_msrs *msrs)
> +{
> + int r = __vcpu_ioctl(vm, vcpuid, KVM_SET_MSRS, msrs);
> +
> + TEST_ASSERT(r == msrs->nmsrs,
> + "KVM_GET_MSRS failed, r: %i (failed on MSR %x)",

Hi, Sean, this should be the "KVM_SET_MSRS failed", right?

> + r, r < 0 || r >= msrs->nmsrs ? -1 : msrs->entries[r].index);
> +}
> +static inline void vcpu_debugregs_get(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_debugregs *debugregs)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_GET_DEBUGREGS, debugregs);
> +}
> +static inline void vcpu_debugregs_set(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_debugregs *debugregs)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_SET_DEBUGREGS, debugregs);
> +}
> +static inline void vcpu_xsave_get(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_xsave *xsave)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_GET_XSAVE, xsave);
> +}
> +static inline void vcpu_xsave2_get(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_xsave *xsave)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_GET_XSAVE2, xsave);
> +}
> +static inline void vcpu_xsave_set(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_xsave *xsave)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_SET_XSAVE, xsave);
> +}
> +static inline void vcpu_xcrs_get(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_xcrs *xcrs)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_GET_XCRS, xcrs);
> +}
> +static inline void vcpu_xcrs_set(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_xcrs *xcrs)
> +{
> + vcpu_ioctl(vm, vcpuid, KVM_SET_XCRS, xcrs);
> +}
> +
> struct kvm_cpuid2 *kvm_get_supported_cpuid(void);
> struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vm *vm, uint32_t vcpuid);
>
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index 9268537f9bd7..5c92e96300c5 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -815,13 +815,11 @@ uint64_t vcpu_get_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index)
> struct kvm_msrs header;
> struct kvm_msr_entry entry;
> } buffer = {};
> - int r;
>
> buffer.header.nmsrs = 1;
> buffer.entry.index = msr_index;
>
> - r = __vcpu_ioctl(vm, vcpuid, KVM_GET_MSRS, &buffer.header);
> - TEST_ASSERT(r == 1, KVM_IOCTL_ERROR(KVM_GET_MSRS, r));
> + vcpu_msrs_get(vm, vcpuid, &buffer.header);
>
> return buffer.entry.data;
> }
> @@ -958,28 +956,26 @@ bool kvm_msr_is_in_save_restore_list(uint32_t msr_index)
> return false;
> }
>
> -static int vcpu_save_xsave_state(struct kvm_vm *vm, struct vcpu *vcpu,
> - struct kvm_x86_state *state)
> +static void vcpu_save_xsave_state(struct kvm_vm *vm, uint32_t vcpuid,
> + struct kvm_x86_state *state)
> {
> - int size;
> + int size = vm_check_cap(vm, KVM_CAP_XSAVE2);
>
> - size = vm_check_cap(vm, KVM_CAP_XSAVE2);
> - if (!size)
> - size = sizeof(struct kvm_xsave);
> -
> - state->xsave = malloc(size);
> - if (size == sizeof(struct kvm_xsave))
> - return ioctl(vcpu->fd, KVM_GET_XSAVE, state->xsave);
> - else
> - return ioctl(vcpu->fd, KVM_GET_XSAVE2, state->xsave);
> + if (size) {
> + state->xsave = malloc(size);
> + vcpu_xsave2_get(vm, vcpuid, state->xsave);
> + } else {
> + state->xsave = malloc(sizeof(struct kvm_xsave));
> + vcpu_xsave_get(vm, vcpuid, state->xsave);
> + }
> }
>
> struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid)
> {
> const struct kvm_msr_list *msr_list = kvm_get_msr_index_list();
> - struct vcpu *vcpu = vcpu_get(vm, vcpuid);
> struct kvm_x86_state *state;
> - int r, i;
> + int i;
> +
> static int nested_size = -1;
>
> if (nested_size == -1) {
> @@ -998,102 +994,54 @@ struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid)
> vcpu_run_complete_io(vm, vcpuid);
>
> state = malloc(sizeof(*state) + msr_list->nmsrs * sizeof(state->msrs.entries[0]));
> - r = ioctl(vcpu->fd, KVM_GET_VCPU_EVENTS, &state->events);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_VCPU_EVENTS, r: %i",
> - r);
>
> - r = ioctl(vcpu->fd, KVM_GET_MP_STATE, &state->mp_state);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_MP_STATE, r: %i",
> - r);
> + vcpu_events_get(vm, vcpuid, &state->events);
> + vcpu_mp_state_get(vm, vcpuid, &state->mp_state);
> + vcpu_regs_get(vm, vcpuid, &state->regs);
> + vcpu_save_xsave_state(vm, vcpuid, state);
>
> - r = ioctl(vcpu->fd, KVM_GET_REGS, &state->regs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_REGS, r: %i",
> - r);
> + if (kvm_check_cap(KVM_CAP_XCRS))
> + vcpu_xcrs_get(vm, vcpuid, &state->xcrs);
>
> - r = vcpu_save_xsave_state(vm, vcpu, state);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_XSAVE, r: %i",
> - r);
> -
> - if (kvm_check_cap(KVM_CAP_XCRS)) {
> - r = ioctl(vcpu->fd, KVM_GET_XCRS, &state->xcrs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_XCRS, r: %i",
> - r);
> - }
> -
> - r = ioctl(vcpu->fd, KVM_GET_SREGS, &state->sregs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_SREGS, r: %i",
> - r);
> + vcpu_sregs_get(vm, vcpuid, &state->sregs);
>
> if (nested_size) {
> state->nested.size = sizeof(state->nested_);
> - r = ioctl(vcpu->fd, KVM_GET_NESTED_STATE, &state->nested);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_NESTED_STATE, r: %i",
> - r);
> +
> + vcpu_nested_state_get(vm, vcpuid, &state->nested);
> TEST_ASSERT(state->nested.size <= nested_size,
> "Nested state size too big, %i (KVM_CHECK_CAP gave %i)",
> state->nested.size, nested_size);
> - } else
> + } else {
> state->nested.size = 0;
> + }
>
> state->msrs.nmsrs = msr_list->nmsrs;
> for (i = 0; i < msr_list->nmsrs; i++)
> state->msrs.entries[i].index = msr_list->indices[i];
> - r = ioctl(vcpu->fd, KVM_GET_MSRS, &state->msrs);
> - TEST_ASSERT(r == msr_list->nmsrs, "Unexpected result from KVM_GET_MSRS, r: %i (failed MSR was 0x%x)",
> - r, r == msr_list->nmsrs ? -1 : msr_list->indices[r]);
> + vcpu_msrs_get(vm, vcpuid, &state->msrs);
>
> - r = ioctl(vcpu->fd, KVM_GET_DEBUGREGS, &state->debugregs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_DEBUGREGS, r: %i",
> - r);
> + vcpu_debugregs_get(vm, vcpuid, &state->debugregs);
>
> return state;
> }
>
> void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_x86_state *state)
> {
> - struct vcpu *vcpu = vcpu_get(vm, vcpuid);
> - int r;
> + vcpu_sregs_set(vm, vcpuid, &state->sregs);
> + vcpu_msrs_set(vm, vcpuid, &state->msrs);
>
> - r = ioctl(vcpu->fd, KVM_SET_SREGS, &state->sregs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_SREGS, r: %i",
> - r);
> + if (kvm_check_cap(KVM_CAP_XCRS))
> + vcpu_xcrs_set(vm, vcpuid, &state->xcrs);
>
> - r = ioctl(vcpu->fd, KVM_SET_MSRS, &state->msrs);
> - TEST_ASSERT(r == state->msrs.nmsrs,
> - "Unexpected result from KVM_SET_MSRS, r: %i (failed at %x)",
> - r, r == state->msrs.nmsrs ? -1 : state->msrs.entries[r].index);
> + vcpu_xsave_set(vm, vcpuid, state->xsave);
> + vcpu_events_set(vm, vcpuid, &state->events);
> + vcpu_mp_state_set(vm, vcpuid, &state->mp_state);
> + vcpu_debugregs_set(vm, vcpuid, &state->debugregs);
> + vcpu_regs_set(vm, vcpuid, &state->regs);
>
> - if (kvm_check_cap(KVM_CAP_XCRS)) {
> - r = ioctl(vcpu->fd, KVM_SET_XCRS, &state->xcrs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_XCRS, r: %i",
> - r);
> - }
> -
> - r = ioctl(vcpu->fd, KVM_SET_XSAVE, state->xsave);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_XSAVE, r: %i",
> - r);
> -
> - r = ioctl(vcpu->fd, KVM_SET_VCPU_EVENTS, &state->events);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_VCPU_EVENTS, r: %i",
> - r);
> -
> - r = ioctl(vcpu->fd, KVM_SET_MP_STATE, &state->mp_state);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_MP_STATE, r: %i",
> - r);
> -
> - r = ioctl(vcpu->fd, KVM_SET_DEBUGREGS, &state->debugregs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_DEBUGREGS, r: %i",
> - r);
> -
> - r = ioctl(vcpu->fd, KVM_SET_REGS, &state->regs);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_REGS, r: %i",
> - r);
> -
> - if (state->nested.size) {
> - r = ioctl(vcpu->fd, KVM_SET_NESTED_STATE, &state->nested);
> - TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_NESTED_STATE, r: %i",
> - r);
> - }
> + if (state->nested.size)
> + vcpu_nested_state_set(vm, vcpuid, &state->nested);
> }
>
> void kvm_x86_state_cleanup(struct kvm_x86_state *state)