From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: [PATCH v4 53/75] x86/sev-es: Handle MSR events Date: Tue, 14 Jul 2020 14:08:55 +0200 Message-ID: <20200714120917.11253-54-joro@8bytes.org> References: <20200714120917.11253-1-joro@8bytes.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200714120917.11253-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org To: x86@kernel.org Cc: Joerg Roedel , Joerg Roedel , Tom Lendacky , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org From: Tom Lendacky Implement a handler for #VC exceptions caused by RDMSR/WRMSR instructions. Signed-off-by: Tom Lendacky [ jroedel@suse.de: Adapt to #VC handling infrastructure ] Co-developed-by: Joerg Roedel Signed-off-by: Joerg Roedel --- 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 bbd839a9d9a1..cbe158091f18 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -407,6 +407,31 @@ 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. @@ -762,6 +787,9 @@ 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; -- 2.27.0