Add Linux's sev_es_ghcb_hv_call helper to allow VMGEXIT from the #VC
handler, and handle SVM_EXIT_WBINVD using this.
Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx>
---
lib/x86/amd_sev_vc.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c
index 142f2cd..27a3ed0 100644
--- a/lib/x86/amd_sev_vc.c
+++ b/lib/x86/amd_sev_vc.c
@@ -52,6 +52,69 @@ static void vc_finish_insn(struct es_em_ctxt *ctxt)
ctxt->regs->rip += ctxt->insn.length;
}
+static inline u64 lower_bits(u64 val, unsigned int bits)
+{
+ u64 mask = (1ULL << bits) - 1;
+
+ return (val & mask);
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+ wrmsr(MSR_AMD64_SEV_ES_GHCB, val);
+}
+
+static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2)
+{
+ enum es_result ret;
+
+ /* Fill in protocol and format specifiers */
+ ghcb->protocol_version = GHCB_PROTOCOL_MAX;
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, exit_code);
+ ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+ ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ if ((ghcb->save.sw_exit_info_1 & 0xffffffff) == 1) {
+ u64 info = ghcb->save.sw_exit_info_2;
+ unsigned long v;
+
+ info = ghcb->save.sw_exit_info_2;
+ v = info & SVM_EVTINJ_VEC_MASK;
+
+ /* Check if exception information from hypervisor is sane. */
+ if ((info & SVM_EVTINJ_VALID) &&
+ ((v == GP_VECTOR) || (v == UD_VECTOR)) &&
+ ((info & SVM_EVTINJ_TYPE_MASK) == SVM_EVTINJ_TYPE_EXEPT)) {
+ ctxt->fi.vector = v;
+ if (info & SVM_EVTINJ_VALID_ERR)
+ ctxt->fi.error_code = info >> 32;
+ ret = ES_EXCEPTION;
+ } else {
+ ret = ES_VMM_ERROR;
+ }
+ } else if (ghcb->save.sw_exit_info_1 & 0xffffffff) {
+ ret = ES_VMM_ERROR;
+ } else {
+ ret = ES_OK;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+}
+
static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
struct ghcb *ghcb,
unsigned long exit_code)
@@ -59,6 +122,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
enum es_result result;
switch (exit_code) {
+ case SVM_EXIT_WBINVD:
+ result = vc_handle_wbinvd(ghcb, ctxt);
+ break;
default:
/*
* Unexpected #VC exception
--
2.32.0
