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    Subject[PATCH v8 1/6] KVM: x86: Consolidate flags for __linearize()
    Date
    Define a 32-bit parameter and consolidate the two bools into it.

    __linearize() has two bool parameters write and fetch. And new flag
    will be needed to support new feature (e.g. LAM needs a flag to skip
    address untag under some conditions).

    No functional change intended.

    In the follow-up patches, the new parameter will be extended for LAM.

    Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
    ---
    arch/x86/kvm/emulate.c | 19 +++++++++++++------
    arch/x86/kvm/kvm_emulate.h | 4 ++++
    2 files changed, 17 insertions(+), 6 deletions(-)

    diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
    index 936a397a08cd..9508836e8a35 100644
    --- a/arch/x86/kvm/emulate.c
    +++ b/arch/x86/kvm/emulate.c
    @@ -687,8 +687,8 @@ static unsigned insn_alignment(struct x86_emulate_ctxt *ctxt, unsigned size)
    static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
    struct segmented_address addr,
    unsigned *max_size, unsigned size,
    - bool write, bool fetch,
    - enum x86emul_mode mode, ulong *linear)
    + u32 flags, enum x86emul_mode mode,
    + ulong *linear)
    {
    struct desc_struct desc;
    bool usable;
    @@ -696,6 +696,8 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
    u32 lim;
    u16 sel;
    u8 va_bits;
    + bool fetch = !!(flags & X86EMUL_F_FETCH);
    + bool write = !!(flags & X86EMUL_F_WRITE);

    la = seg_base(ctxt, addr.seg) + addr.ea;
    *max_size = 0;
    @@ -757,7 +759,11 @@ static int linearize(struct x86_emulate_ctxt *ctxt,
    ulong *linear)
    {
    unsigned max_size;
    - return __linearize(ctxt, addr, &max_size, size, write, false,
    + u32 flags = 0;
    +
    + if (write)
    + flags |= X86EMUL_F_WRITE;
    + return __linearize(ctxt, addr, &max_size, size, flags,
    ctxt->mode, linear);
    }

    @@ -768,10 +774,11 @@ static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst)
    unsigned max_size;
    struct segmented_address addr = { .seg = VCPU_SREG_CS,
    .ea = dst };
    + u32 flags = X86EMUL_F_FETCH;

    if (ctxt->op_bytes != sizeof(unsigned long))
    addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1);
    - rc = __linearize(ctxt, addr, &max_size, 1, false, true, ctxt->mode, &linear);
    + rc = __linearize(ctxt, addr, &max_size, 1, flags, ctxt->mode, &linear);
    if (rc == X86EMUL_CONTINUE)
    ctxt->_eip = addr.ea;
    return rc;
    @@ -896,6 +903,7 @@ static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
    int cur_size = ctxt->fetch.end - ctxt->fetch.data;
    struct segmented_address addr = { .seg = VCPU_SREG_CS,
    .ea = ctxt->eip + cur_size };
    + u32 flags = X86EMUL_F_FETCH;

    /*
    * We do not know exactly how many bytes will be needed, and
    @@ -907,8 +915,7 @@ static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
    * boundary check itself. Instead, we use max_size to check
    * against op_size.
    */
    - rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode,
    - &linear);
    + rc = __linearize(ctxt, addr, &max_size, 0, flags, ctxt->mode, &linear);
    if (unlikely(rc != X86EMUL_CONTINUE))
    return rc;

    diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
    index ab65f3a47dfd..5b9ec610b2cb 100644
    --- a/arch/x86/kvm/kvm_emulate.h
    +++ b/arch/x86/kvm/kvm_emulate.h
    @@ -88,6 +88,10 @@ struct x86_instruction_info {
    #define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */
    #define X86EMUL_INTERCEPTED 6 /* Intercepted by nested VMCB/VMCS */

    +/* x86-specific emulation flags */
    +#define X86EMUL_F_FETCH BIT(0)
    +#define X86EMUL_F_WRITE BIT(1)
    +
    struct x86_emulate_ops {
    void (*vm_bugged)(struct x86_emulate_ctxt *ctxt);
    /*
    --
    2.25.1
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