From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38317) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYdAy-0007ce-7m for qemu-devel@nongnu.org; Thu, 28 Jun 2018 16:05:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYdAx-0000y1-7v for qemu-devel@nongnu.org; Thu, 28 Jun 2018 16:05:56 -0400 Received: from mail-wr0-x242.google.com ([2a00:1450:400c:c0c::242]:43835) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fYdAx-0000wu-0S for qemu-devel@nongnu.org; Thu, 28 Jun 2018 16:05:55 -0400 Received: by mail-wr0-x242.google.com with SMTP id c5-v6so6682014wrs.10 for ; Thu, 28 Jun 2018 13:05:54 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Thu, 28 Jun 2018 22:04:51 +0200 Message-Id: <1530216310-52873-42-git-send-email-pbonzini@redhat.com> In-Reply-To: <1530216310-52873-1-git-send-email-pbonzini@redhat.com> References: <1530216310-52873-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PULL 41/60] WHPX: register for unrecognized MSR exits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Justin Terry (VM)" From: "Justin Terry (VM)" Some variations of Linux kernels end up accessing MSR's that the Windows Hypervisor doesn't implement which causes a GP to be returned to the guest. This fix registers QEMU for unimplemented MSR access and globally returns 0 on reads and ignores writes. This behavior is allows the Linux kernel to probe the MSR with a write/read/check sequence it does often without failing the access. Signed-off-by: Justin Terry (VM) Message-Id: <20180605221500.21674-2-juterry@microsoft.com> Signed-off-by: Paolo Bonzini --- target/i386/whpx-all.c | 41 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 38 insertions(+), 3 deletions(-) diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c index 99501ba..57e53e1 100644 --- a/target/i386/whpx-all.c +++ b/target/i386/whpx-all.c @@ -932,6 +932,7 @@ static int whpx_vcpu_run(CPUState *cpu) case WHvRunVpExitReasonX64InterruptWindow: vcpu->window_registered = 0; + ret = 0; break; case WHvRunVpExitReasonX64Halt: @@ -943,6 +944,40 @@ static int whpx_vcpu_run(CPUState *cpu) ret = 1; break; + case WHvRunVpExitReasonX64MsrAccess: { + WHV_REGISTER_VALUE reg_values[3] = {0}; + WHV_REGISTER_NAME reg_names[3]; + UINT32 reg_count; + + reg_names[0] = WHvX64RegisterRip; + reg_names[1] = WHvX64RegisterRax; + reg_names[2] = WHvX64RegisterRdx; + + reg_values[0].Reg64 = + vcpu->exit_ctx.VpContext.Rip + + vcpu->exit_ctx.VpContext.InstructionLength; + + /* + * For all unsupported MSR access we: + * ignore writes + * return 0 on read. + */ + reg_count = vcpu->exit_ctx.MsrAccess.AccessInfo.IsWrite ? + 1 : 3; + + hr = whp_dispatch.WHvSetVirtualProcessorRegisters( + whpx->partition, + cpu->cpu_index, + reg_names, reg_count, + reg_values); + + if (FAILED(hr)) { + error_report("WHPX: Failed to set MsrAccess state " + " registers, hr=%08lx", hr); + } + ret = 0; + break; + } case WHvRunVpExitReasonX64Cpuid: { WHV_REGISTER_VALUE reg_values[5]; WHV_REGISTER_NAME reg_names[5]; @@ -1010,7 +1045,6 @@ static int whpx_vcpu_run(CPUState *cpu) case WHvRunVpExitReasonUnrecoverableException: case WHvRunVpExitReasonInvalidVpRegisterValue: case WHvRunVpExitReasonUnsupportedFeature: - case WHvRunVpExitReasonX64MsrAccess: case WHvRunVpExitReasonException: default: error_report("WHPX: Unexpected VP exit code %d", @@ -1378,6 +1412,7 @@ static int whpx_accel_init(MachineState *ms) } memset(&prop, 0, sizeof(WHV_PARTITION_PROPERTY)); + prop.ExtendedVmExits.X64MsrExit = 1; prop.ExtendedVmExits.X64CpuidExit = 1; hr = whp_dispatch.WHvSetPartitionProperty( whpx->partition, @@ -1386,8 +1421,8 @@ static int whpx_accel_init(MachineState *ms) sizeof(WHV_PARTITION_PROPERTY)); if (FAILED(hr)) { - error_report("WHPX: Failed to enable partition extended X64CpuidExit" - " hr=%08lx", hr); + error_report("WHPX: Failed to enable partition extended X64MsrExit and" + " X64CpuidExit hr=%08lx", hr); ret = -EINVAL; goto error; } -- 1.8.3.1