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authorTom Lendacky <thomas.lendacky@amd.com>2020-09-07 15:15:52 +0200
committerBorislav Petkov <bp@suse.de>2020-09-09 11:33:19 +0200
commita4afa6081c88701635e1e20090f953a25f9444e0 (patch)
treeaacea9a1b1f68a44d90c92c5bb2dd4f232997ce8 /arch/x86/kernel/sev-es.c
parent0118b604c2c94c6e34982015cfa7891af4764786 (diff)
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x86/sev-es: Handle MSR events
Implement a handler for #VC exceptions caused by RDMSR/WRMSR instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure. ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-52-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel/sev-es.c')
-rw-r--r--arch/x86/kernel/sev-es.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index f724b75ad235..620510070a1a 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -393,6 +393,31 @@ static bool vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
/* Include code shared with pre-decompression boot stage */
#include "sev-es-shared.c"
+static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct pt_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->cx);
+ if (exit_info_1) {
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rdx(ghcb, regs->dx);
+ }
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+
+ if ((ret == ES_OK) && (!exit_info_1)) {
+ regs->ax = ghcb->save.rax;
+ regs->dx = ghcb->save.rdx;
+ }
+
+ return ret;
+}
+
/*
* This function runs on the first #VC exception after the kernel
* switched to virtual addresses.
@@ -756,6 +781,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
case SVM_EXIT_IOIO:
result = vc_handle_ioio(ghcb, ctxt);
break;
+ case SVM_EXIT_MSR:
+ result = vc_handle_msr(ghcb, ctxt);
+ break;
case SVM_EXIT_NPF:
result = vc_handle_mmio(ghcb, ctxt);
break;