Re: [PATCH v3 02/11] KVM: SVM: Change intercept_cr to generic intercepts

Jim Mattson
2020-07-28T23:56:35Z

On Tue, Jul 28, 2020 at 4:38 PM Babu Moger <babu.moger@amd.com> wrote:
>
> Change intercept_cr to generic intercepts in vmcb_control_area.
> Use the new __set_intercept, __clr_intercept and __is_intercept
> where applicable.
>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
> arch/x86/include/asm/svm.h | 42 ++++++++++++++++++++++++++++++++----------
> arch/x86/kvm/svm/nested.c | 26 +++++++++++++++++---------
> arch/x86/kvm/svm/svm.c | 4 ++--
> arch/x86/kvm/svm/svm.h | 6 +++---
> 4 files changed, 54 insertions(+), 24 deletions(-)
>
> diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
> index 8a1f5382a4ea..d4739f4eae63 100644
> --- a/arch/x86/include/asm/svm.h
> +++ b/arch/x86/include/asm/svm.h
> @@ -4,6 +4,37 @@
>
> #include <uapi/asm/svm.h>
>
> +/*
> + * VMCB Control Area intercept bits starting
> + * at Byte offset 000h (Vector 0).
> + */
> +
> +enum vector_offset {
> + CR_VECTOR = 0,
> + MAX_VECTORS,
> +};
> +
> +enum {
> + /* Byte offset 000h (Vector 0) */
> + INTERCEPT_CR0_READ = 0,
> + INTERCEPT_CR1_READ,
> + INTERCEPT_CR2_READ,
> + INTERCEPT_CR3_READ,
> + INTERCEPT_CR4_READ,
> + INTERCEPT_CR5_READ,
> + INTERCEPT_CR6_READ,
> + INTERCEPT_CR7_READ,
> + INTERCEPT_CR8_READ,
> + INTERCEPT_CR0_WRITE = 16,
> + INTERCEPT_CR1_WRITE,
> + INTERCEPT_CR2_WRITE,
> + INTERCEPT_CR3_WRITE,
> + INTERCEPT_CR4_WRITE,
> + INTERCEPT_CR5_WRITE,
> + INTERCEPT_CR6_WRITE,
> + INTERCEPT_CR7_WRITE,
> + INTERCEPT_CR8_WRITE,
> +};
>
> enum {
> INTERCEPT_INTR,
> @@ -57,7 +88,7 @@ enum {
>
>
> struct __attribute__ ((__packed__)) vmcb_control_area {
> - u32 intercept_cr;
> + u32 intercepts[MAX_VECTORS];
> u32 intercept_dr;
> u32 intercept_exceptions;
> u64 intercept;
> @@ -240,15 +271,6 @@ struct __attribute__ ((__packed__)) vmcb {
> #define SVM_SELECTOR_READ_MASK SVM_SELECTOR_WRITE_MASK
> #define SVM_SELECTOR_CODE_MASK (1 << 3)
>
> -#define INTERCEPT_CR0_READ 0
> -#define INTERCEPT_CR3_READ 3
> -#define INTERCEPT_CR4_READ 4
> -#define INTERCEPT_CR8_READ 8
> -#define INTERCEPT_CR0_WRITE (16 + 0)
> -#define INTERCEPT_CR3_WRITE (16 + 3)
> -#define INTERCEPT_CR4_WRITE (16 + 4)
> -#define INTERCEPT_CR8_WRITE (16 + 8)
> -
> #define INTERCEPT_DR0_READ 0
> #define INTERCEPT_DR1_READ 1
> #define INTERCEPT_DR2_READ 2
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index 6bceafb19108..46f5c82d9b45 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -105,6 +105,7 @@ static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
> void recalc_intercepts(struct vcpu_svm *svm)
> {
> struct vmcb_control_area *c, *h, *g;
> + unsigned int i;
>
> mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
>
> @@ -117,15 +118,17 @@ void recalc_intercepts(struct vcpu_svm *svm)
>
> svm->nested.host_intercept_exceptions = h->intercept_exceptions;
>
> - c->intercept_cr = h->intercept_cr;
> + for (i = 0; i < MAX_VECTORS; i++)
> + c->intercepts[i] = h->intercepts[i];
> +
> c->intercept_dr = h->intercept_dr;
> c->intercept_exceptions = h->intercept_exceptions;
> c->intercept = h->intercept;
>
> if (g->int_ctl & V_INTR_MASKING_MASK) {
> /* We only want the cr8 intercept bits of L1 */
> - c->intercept_cr &= ~(1U << INTERCEPT_CR8_READ);
> - c->intercept_cr &= ~(1U << INTERCEPT_CR8_WRITE);
> + __clr_intercept(&c->intercepts, INTERCEPT_CR8_READ);
> + __clr_intercept(&c->intercepts, INTERCEPT_CR8_WRITE);

Why the direct calls to the __clr_intercept worker function? Can't
these be calls to clr_cr_intercept()?
Likewise throughout.