The following commit has been merged into the x86/seves branch of tip: Commit-ID: a4afa6081c88701635e1e20090f953a25f9444e0 Gitweb: https://git.kernel.org/tip/a4afa6081c88701635e1e20090f953a25f9444e0 Author: Tom Lendacky <[email protected]> AuthorDate: Mon, 07 Sep 2020 15:15:52 +02:00 Committer: Borislav Petkov <[email protected]> CommitterDate: Wed, 09 Sep 2020 11:33:19 +02:00
x86/sev-es: Handle MSR events Implement a handler for #VC exceptions caused by RDMSR/WRMSR instructions. Signed-off-by: Tom Lendacky <[email protected]> [ [email protected]: Adapt to #VC handling infrastructure. ] Co-developed-by: Joerg Roedel <[email protected]> Signed-off-by: Joerg Roedel <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected] --- arch/x86/kernel/sev-es.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index f724b75..6205100 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;
