[PATCH 55/70] x86/sev-es: Handle RDTSCP Events

Joerg Roedel
2020-03-19T09:16:32Z

From: Joerg Roedel <jroedel@suse.de>

Extend the RDTSC handler to also handle RDTSCP events.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
arch/x86/kernel/sev-es.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index a4f136b2e149..11947b648b43 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -665,19 +665,25 @@ static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
}

-static enum es_result vc_handle_rdtsc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
{
+ bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
enum es_result ret;

- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDTSC, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
if (ret != ES_OK)
return ret;

- if (!(ghcb_is_valid_rax(ghcb) && ghcb_is_valid_rdx(ghcb)))
+ if (!(ghcb_is_valid_rax(ghcb) && ghcb_is_valid_rdx(ghcb) &&
+ (!rdtscp || ghcb_is_valid_rcx(ghcb))))
return ES_VMM_ERROR;

ctxt->regs->ax = ghcb->save.rax;
ctxt->regs->dx = ghcb->save.rdx;
+ if (rdtscp)
+ ctxt->regs->cx = ghcb->save.rcx;

return ES_OK;
}
@@ -716,7 +722,8 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
result = vc_handle_dr7_write(ghcb, ctxt, early);
break;
case SVM_EXIT_RDTSC:
- result = vc_handle_rdtsc(ghcb, ctxt);
+ case SVM_EXIT_RDTSCP:
+ result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
break;
case SVM_EXIT_RDPMC:
result = vc_handle_rdpmc(ghcb, ctxt);
--
2.17.1