From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: [PATCH v3 62/75] x86/sev-es: Handle #AC Events Date: Tue, 28 Apr 2020 17:17:12 +0200 Message-ID: <20200428151725.31091-63-joro@8bytes.org> References: <20200428151725.31091-1-joro@8bytes.org> Return-path: In-Reply-To: <20200428151725.31091-1-joro@8bytes.org> Sender: kvm-owner@vger.kernel.org To: x86@kernel.org Cc: hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Thomas Hellstrom , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Joerg Roedel , Joerg Roedel , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org From: Joerg Roedel Implement a handler for #VC exceptions caused by #AC exceptions. The #AC exception is just forwarded to do_alignment_check() and not pushed down to the hypervisor, as requested by the SEV-ES GHCB Standardization Specification. Signed-off-by: Joerg Roedel --- arch/x86/kernel/sev-es.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index f807a2adcbe3..050a15da9ae5 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -869,6 +869,19 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb, return ES_OK; } +static enum es_result vc_handle_trap_ac(struct ghcb *ghcb, + struct es_em_ctxt *ctxt) +{ + /* + * Calling do_alignment_check() directly does not work, because it + * enables IRQs and the GHCB is active. Forward the exception and call + * it later from vc_forward_exception(). + */ + ctxt->fi.vector = X86_TRAP_AC; + ctxt->fi.error_code = 0; + return ES_EXCEPTION; +} + static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, struct ghcb *ghcb, unsigned long exit_code) @@ -882,6 +895,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, case SVM_EXIT_WRITE_DR7: result = vc_handle_dr7_write(ghcb, ctxt); break; + case SVM_EXIT_EXCP_BASE + X86_TRAP_AC: + result = vc_handle_trap_ac(ghcb, ctxt); + break; case SVM_EXIT_RDTSC: case SVM_EXIT_RDTSCP: result = vc_handle_rdtsc(ghcb, ctxt, exit_code); @@ -941,6 +957,9 @@ static void vc_forward_exception(struct es_em_ctxt *ctxt) case X86_TRAP_UD: do_invalid_op(ctxt->regs, 0); break; + case X86_TRAP_AC: + do_alignment_check(ctxt->regs, error_code); + break; default: pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n"); BUG(); -- 2.17.1