On Wed, Feb 9, 2022 at 8:44 AM Varad Gautam <varad.gautam@xxxxxxxx> wrote:
>
> Using Linux's IOIO #VC processing logic.
>
> Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx>
> ---
> lib/x86/amd_sev_vc.c | 146 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 146 insertions(+)
>
> diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c
> index 401cb29..88c95e1 100644
> --- a/lib/x86/amd_sev_vc.c
> +++ b/lib/x86/amd_sev_vc.c
> @@ -172,6 +172,149 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
> return ret;
> }
>
> +#define IOIO_TYPE_STR BIT(2)
> +#define IOIO_TYPE_IN 1
> +#define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR)
> +#define IOIO_TYPE_OUT 0
> +#define IOIO_TYPE_OUTS (IOIO_TYPE_OUT | IOIO_TYPE_STR)
> +
> +#define IOIO_REP BIT(3)
> +
> +#define IOIO_ADDR_64 BIT(9)
> +#define IOIO_ADDR_32 BIT(8)
> +#define IOIO_ADDR_16 BIT(7)
> +
> +#define IOIO_DATA_32 BIT(6)
> +#define IOIO_DATA_16 BIT(5)
> +#define IOIO_DATA_8 BIT(4)
> +
> +#define IOIO_SEG_ES (0 << 10)
> +#define IOIO_SEG_DS (3 << 10)
> +
> +static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo)
> +{
> + struct insn *insn = &ctxt->insn;
> + *exitinfo = 0;
> +
> + switch (insn->opcode.bytes[0]) {
> + /* INS opcodes */
> + case 0x6c:
> + case 0x6d:
> + *exitinfo |= IOIO_TYPE_INS;
> + *exitinfo |= IOIO_SEG_ES;
> + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16;
> + break;
> +
> + /* OUTS opcodes */
> + case 0x6e:
> + case 0x6f:
> + *exitinfo |= IOIO_TYPE_OUTS;
> + *exitinfo |= IOIO_SEG_DS;
> + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16;
> + break;
> +
> + /* IN immediate opcodes */
> + case 0xe4:
> + case 0xe5:
> + *exitinfo |= IOIO_TYPE_IN;
> + *exitinfo |= (u8)insn->immediate.value << 16;
> + break;
> +
> + /* OUT immediate opcodes */
> + case 0xe6:
> + case 0xe7:
> + *exitinfo |= IOIO_TYPE_OUT;
> + *exitinfo |= (u8)insn->immediate.value << 16;
> + break;
> +
> + /* IN register opcodes */
> + case 0xec:
> + case 0xed:
> + *exitinfo |= IOIO_TYPE_IN;
> + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16;
> + break;
> +
> + /* OUT register opcodes */
> + case 0xee:
> + case 0xef:
> + *exitinfo |= IOIO_TYPE_OUT;
> + *exitinfo |= (ctxt->regs->rdx & 0xffff) << 16;
> + break;
> +
> + default:
> + return ES_DECODE_FAILED;
> + }
> +
> + switch (insn->opcode.bytes[0]) {
> + case 0x6c:
> + case 0x6e:
> + case 0xe4:
> + case 0xe6:
> + case 0xec:
> + case 0xee:
> + /* Single byte opcodes */
> + *exitinfo |= IOIO_DATA_8;
> + break;
> + default:
> + /* Length determined by instruction parsing */
> + *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16
> + : IOIO_DATA_32;
> + }
> + switch (insn->addr_bytes) {
> + case 2:
> + *exitinfo |= IOIO_ADDR_16;
> + break;
> + case 4:
> + *exitinfo |= IOIO_ADDR_32;
> + break;
> + case 8:
> + *exitinfo |= IOIO_ADDR_64;
> + break;
> + }
> +
> + if (insn_has_rep_prefix(insn))
> + *exitinfo |= IOIO_REP;
> +
> + return ES_OK;
> +}
> +
> +static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
> +{
> + struct ex_regs *regs = ctxt->regs;
> + u64 exit_info_1;
> + enum es_result ret;
> +
> + ret = vc_ioio_exitinfo(ctxt, &exit_info_1);
> + if (ret != ES_OK)
> + return ret;
> +
> + if (exit_info_1 & IOIO_TYPE_STR) {
> + ret = ES_VMM_ERROR;
> + } else {
> + /* IN/OUT into/from rAX */
> +
> + int bits = (exit_info_1 & 0x70) >> 1;
> + u64 rax = 0;
> +
> + if (!(exit_info_1 & IOIO_TYPE_IN))
> + rax = lower_bits(regs->rax, bits);
> +
> + ghcb_set_rax(ghcb, rax);
> +
> + ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
> + if (ret != ES_OK)
> + return ret;
> +
> + if (exit_info_1 & IOIO_TYPE_IN) {
> + if (!ghcb_rax_is_valid(ghcb))
> + return ES_VMM_ERROR;
> + regs->rax = lower_bits(ghcb->save.rax, bits);
> + }
> + }
> +
> + return ret;
> +}
> +
> static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
> struct ghcb *ghcb,
> unsigned long exit_code)
> @@ -185,6 +328,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
> case SVM_EXIT_MSR:
> result = vc_handle_msr(ghcb, ctxt);
> break;
> + case SVM_EXIT_IOIO:
> + result = vc_handle_ioio(ghcb, ctxt);
> + break;
> default:
> /*
> * Unexpected #VC exception
> --
> 2.32.0
>
Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
