----- Original Message -----
> From: "Steve Rutherford" <srutherford@xxxxxxxxxx>
> To: kvm@xxxxxxxxxxxxxxx
> Cc: pbonzini@xxxxxxxxxx, dvyukov@xxxxxxxxxx, rkrcmar@xxxxxxxxxx, ppandit@xxxxxxxxxx, kernellwp@xxxxxxxxx
> Sent: Thursday, January 12, 2017 3:28:29 AM
> Subject: [PATCH] KVM: x86: Introduce segmented_write_std
>
> Introduces segemented_write_std.
>
> Switches from emulated reads/writes to standard read/writes in fxsave,
> fxrstor, sgdt, and sidt.
>
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Steve Rutherford <srutherford@xxxxxxxxxx>
> ---
> arch/x86/kvm/emulate.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index 2b8349a2b14b..ad258aa0b302 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -819,6 +819,20 @@ static int segmented_read_std(struct x86_emulate_ctxt
> *ctxt,
> return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
> }
>
> +static int segmented_write_std(struct x86_emulate_ctxt *ctxt,
> + struct segmented_address addr,
> + void *data,
> + unsigned int size)
> +{
> + int rc;
> + ulong linear;
> +
> + rc = linearize(ctxt, addr, size, true, &linear);
> + if (rc != X86EMUL_CONTINUE)
> + return rc;
> + return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception);
> +}
> +
> /*
> * Prefetch the remaining bytes of the instruction without crossing page
> * boundary if they are not in fetch_cache yet.
> @@ -3686,8 +3700,8 @@ static int emulate_store_desc_ptr(struct
> x86_emulate_ctxt *ctxt,
> }
> /* Disable writeback. */
> ctxt->dst.type = OP_NONE;
> - return segmented_write(ctxt, ctxt->dst.addr.mem,
> - &desc_ptr, 2 + ctxt->op_bytes);
> + return segmented_write_std(ctxt, ctxt->dst.addr.mem,
> + &desc_ptr, 2 + ctxt->op_bytes);
> }
>
> static int em_sgdt(struct x86_emulate_ctxt *ctxt)
> @@ -3933,7 +3947,7 @@ static int em_fxsave(struct x86_emulate_ctxt *ctxt)
> else
> size = offsetof(struct fxregs_state, xmm_space[0]);
>
> - return segmented_write(ctxt, ctxt->memop.addr.mem, &fx_state, size);
> + return segmented_write_std(ctxt, ctxt->memop.addr.mem, &fx_state, size);
> }
>
> static int fxrstor_fixup(struct x86_emulate_ctxt *ctxt,
> @@ -3975,7 +3989,7 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
> if (rc != X86EMUL_CONTINUE)
> return rc;
>
> - rc = segmented_read(ctxt, ctxt->memop.addr.mem, &fx_state, 512);
> + rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, 512);
> if (rc != X86EMUL_CONTINUE)
> return rc;
>
> --
> 2.11.0.390.gc69c2f50cf-goog
>
>
Queued for 4.10, thanks. At least fxsave/fxrstor is not in any
released version, but that was close. I owe Dmitry some (more) beer.
Paolo
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