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    Subject[RFC PATCH v2 61/69] KVM: VMX: Move AR_BYTES encoder/decoder helpers to common.h
    Date
    From: Sean Christopherson <sean.j.christopherson@intel.com>

    Move the AR_BYTES helpers to common.h so that future patches can reuse
    them to decode/encode AR for TDX.

    Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
    Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
    ---
    arch/x86/kvm/vmx/common.h | 41 ++++++++++++++++++++++++++++++++++
    arch/x86/kvm/vmx/vmx.c | 47 ++++-----------------------------------
    2 files changed, 45 insertions(+), 43 deletions(-)

    diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
    index aa6a569b87d1..755aaec85199 100644
    --- a/arch/x86/kvm/vmx/common.h
    +++ b/arch/x86/kvm/vmx/common.h
    @@ -4,6 +4,7 @@

    #include <linux/kvm_host.h>

    +#include <asm/kvm.h>
    #include <asm/traps.h>
    #include <asm/vmx.h>

    @@ -119,4 +120,44 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
    return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
    }

    +static inline u32 vmx_encode_ar_bytes(struct kvm_segment *var)
    +{
    + u32 ar;
    +
    + if (var->unusable || !var->present)
    + ar = 1 << 16;
    + else {
    + ar = var->type & 15;
    + ar |= (var->s & 1) << 4;
    + ar |= (var->dpl & 3) << 5;
    + ar |= (var->present & 1) << 7;
    + ar |= (var->avl & 1) << 12;
    + ar |= (var->l & 1) << 13;
    + ar |= (var->db & 1) << 14;
    + ar |= (var->g & 1) << 15;
    + }
    +
    + return ar;
    +}
    +
    +static inline void vmx_decode_ar_bytes(u32 ar, struct kvm_segment *var)
    +{
    + var->unusable = (ar >> 16) & 1;
    + var->type = ar & 15;
    + var->s = (ar >> 4) & 1;
    + var->dpl = (ar >> 5) & 3;
    + /*
    + * Some userspaces do not preserve unusable property. Since usable
    + * segment has to be present according to VMX spec we can use present
    + * property to amend userspace bug by making unusable segment always
    + * nonpresent. vmx_encode_ar_bytes() already marks nonpresent
    + * segment as unusable.
    + */
    + var->present = !var->unusable;
    + var->avl = (ar >> 12) & 1;
    + var->l = (ar >> 13) & 1;
    + var->db = (ar >> 14) & 1;
    + var->g = (ar >> 15) & 1;
    +}
    +
    #endif /* __KVM_X86_VMX_COMMON_H */
    diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
    index 3c3bfc80d2bb..40843ca2fb33 100644
    --- a/arch/x86/kvm/vmx/vmx.c
    +++ b/arch/x86/kvm/vmx/vmx.c
    @@ -365,8 +365,6 @@ static const struct kernel_param_ops vmentry_l1d_flush_ops = {
    };
    module_param_cb(vmentry_l1d_flush, &vmentry_l1d_flush_ops, NULL, 0644);

    -static u32 vmx_segment_access_rights(struct kvm_segment *var);
    -
    void vmx_vmexit(void);

    #define vmx_insn_failed(fmt...) \
    @@ -2826,7 +2824,7 @@ static void fix_rmode_seg(int seg, struct kvm_segment *save)
    vmcs_write16(sf->selector, var.selector);
    vmcs_writel(sf->base, var.base);
    vmcs_write32(sf->limit, var.limit);
    - vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(&var));
    + vmcs_write32(sf->ar_bytes, vmx_encode_ar_bytes(&var));
    }

    static void enter_rmode(struct kvm_vcpu *vcpu)
    @@ -3217,7 +3215,6 @@ void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
    void vmx_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg)
    {
    struct vcpu_vmx *vmx = to_vmx(vcpu);
    - u32 ar;

    if (vmx->rmode.vm86_active && seg != VCPU_SREG_LDTR) {
    *var = vmx->rmode.segs[seg];
    @@ -3231,23 +3228,7 @@ void vmx_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg)
    var->base = vmx_read_guest_seg_base(vmx, seg);
    var->limit = vmx_read_guest_seg_limit(vmx, seg);
    var->selector = vmx_read_guest_seg_selector(vmx, seg);
    - ar = vmx_read_guest_seg_ar(vmx, seg);
    - var->unusable = (ar >> 16) & 1;
    - var->type = ar & 15;
    - var->s = (ar >> 4) & 1;
    - var->dpl = (ar >> 5) & 3;
    - /*
    - * Some userspaces do not preserve unusable property. Since usable
    - * segment has to be present according to VMX spec we can use present
    - * property to amend userspace bug by making unusable segment always
    - * nonpresent. vmx_segment_access_rights() already marks nonpresent
    - * segment as unusable.
    - */
    - var->present = !var->unusable;
    - var->avl = (ar >> 12) & 1;
    - var->l = (ar >> 13) & 1;
    - var->db = (ar >> 14) & 1;
    - var->g = (ar >> 15) & 1;
    + vmx_decode_ar_bytes(vmx_read_guest_seg_ar(vmx, seg), var);
    }

    static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
    @@ -3273,26 +3254,6 @@ int vmx_get_cpl(struct kvm_vcpu *vcpu)
    }
    }

    -static u32 vmx_segment_access_rights(struct kvm_segment *var)
    -{
    - u32 ar;
    -
    - if (var->unusable || !var->present)
    - ar = 1 << 16;
    - else {
    - ar = var->type & 15;
    - ar |= (var->s & 1) << 4;
    - ar |= (var->dpl & 3) << 5;
    - ar |= (var->present & 1) << 7;
    - ar |= (var->avl & 1) << 12;
    - ar |= (var->l & 1) << 13;
    - ar |= (var->db & 1) << 14;
    - ar |= (var->g & 1) << 15;
    - }
    -
    - return ar;
    -}
    -
    void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg)
    {
    struct vcpu_vmx *vmx = to_vmx(vcpu);
    @@ -3327,7 +3288,7 @@ void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg)
    if (is_unrestricted_guest(vcpu) && (seg != VCPU_SREG_LDTR))
    var->type |= 0x1; /* Accessed */

    - vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(var));
    + vmcs_write32(sf->ar_bytes, vmx_encode_ar_bytes(var));

    out:
    vmx->emulation_required = emulation_required(vcpu);
    @@ -3374,7 +3335,7 @@ static bool rmode_segment_valid(struct kvm_vcpu *vcpu, int seg)
    var.dpl = 0x3;
    if (seg == VCPU_SREG_CS)
    var.type = 0x3;
    - ar = vmx_segment_access_rights(&var);
    + ar = vmx_encode_ar_bytes(&var);

    if (var.base != (var.selector << 4))
    return false;
    --
    2.25.1
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