On Wed, Feb 9, 2022 at 8:44 AM Varad Gautam <varad.gautam@xxxxxxxx> wrote:
>
> Using Linux's MSR #VC processing logic.
>
> Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx>
> ---
> lib/x86/amd_sev_vc.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c
> index 9ee67c0..401cb29 100644
> --- a/lib/x86/amd_sev_vc.c
> +++ b/lib/x86/amd_sev_vc.c
> @@ -147,6 +147,31 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
> return ES_OK;
> }
>
> +static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
> +{
> + struct ex_regs *regs = ctxt->regs;
> + enum es_result ret;
> + u64 exit_info_1;
> +
> + /* Is it a WRMSR? */
> + exit_info_1 = (ctxt->insn.opcode.bytes[1] == 0x30) ? 1 : 0;
> +
> + ghcb_set_rcx(ghcb, regs->rcx);
> + if (exit_info_1) {
> + ghcb_set_rax(ghcb, regs->rax);
> + ghcb_set_rdx(ghcb, regs->rdx);
> + }
> +
> + ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
> +
> + if ((ret == ES_OK) && (!exit_info_1)) {
> + regs->rax = ghcb->save.rax;
> + regs->rdx = ghcb->save.rdx;
> + }
> +
> + return ret;
> +}
> +
> static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
> struct ghcb *ghcb,
> unsigned long exit_code)
> @@ -157,6 +182,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
> case SVM_EXIT_CPUID:
> result = vc_handle_cpuid(ghcb, ctxt);
> break;
> + case SVM_EXIT_MSR:
> + result = vc_handle_msr(ghcb, ctxt);
> + break;
> default:
> /*
> * Unexpected #VC exception
> --
> 2.32.0
>
Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
