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    Subject[PATCH v3 1/4] KVM: x86: add Align16 instruction flag
    Date
    Needed for FXSAVE and FXRSTOR.

    Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
    ---
    v2: split into a separate patch
    ---
    arch/x86/kvm/emulate.c | 20 ++++++++++++--------
    1 file changed, 12 insertions(+), 8 deletions(-)

    diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
    index cbd7b92585bb..eb74d3b56e1c 100644
    --- a/arch/x86/kvm/emulate.c
    +++ b/arch/x86/kvm/emulate.c
    @@ -171,6 +171,7 @@
    #define NearBranch ((u64)1 << 52) /* Near branches */
    #define No16 ((u64)1 << 53) /* No 16 bit operand */
    #define IncSP ((u64)1 << 54) /* SP is incremented before ModRM calc */
    +#define Aligned16 ((u64)1 << 55) /* Aligned to 16 byte boundary (e.g. FXSAVE) */

    #define DstXacc (DstAccLo | SrcAccHi | SrcWrite)

    @@ -632,21 +633,24 @@ static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector,
    * depending on whether they're AVX encoded or not.
    *
    * Also included is CMPXCHG16B which is not a vector instruction, yet it is
    - * subject to the same check.
    + * subject to the same check. FXSAVE and FXRSTOR are checked here too as their
    + * 512 bytes of data must be aligned to a 16 byte boundary.
    */
    -static bool insn_aligned(struct x86_emulate_ctxt *ctxt, unsigned size)
    +static unsigned insn_alignment(struct x86_emulate_ctxt *ctxt, unsigned size)
    {
    if (likely(size < 16))
    - return false;
    + return 1;

    if (ctxt->d & Aligned)
    - return true;
    + return size;
    else if (ctxt->d & Unaligned)
    - return false;
    + return 1;
    else if (ctxt->d & Avx)
    - return false;
    + return 1;
    + else if (ctxt->d & Aligned16)
    + return 16;
    else
    - return true;
    + return size;
    }

    static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
    @@ -704,7 +708,7 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
    }
    break;
    }
    - if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
    + if (la & (insn_alignment(ctxt, size) - 1))
    return emulate_gp(ctxt, 0);
    return X86EMUL_CONTINUE;
    bad:
    --
    2.10.2
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