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[Qemu-devel] [PATCH 1/2] WHPX workaround bug in OSVW handling
From: |
Justin Terry (VM) |
Subject: |
[Qemu-devel] [PATCH 1/2] WHPX workaround bug in OSVW handling |
Date: |
Tue, 5 Jun 2018 22:15:27 +0000 |
Adds a workaround to an incorrect value setting
CPUID Fn8000_0001_ECX[bit 9 OSVW] = 1. This can cause a guest linux kernel
to panic when an issue to rdmsr C001_0140h returns 0. Disabling this feature
correctly allows the guest to boot without accessing the osv workarounds.
Signed-off-by: Justin Terry (VM) <address@hidden>
---
target/i386/whpx-all.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c
index 6b42096698..99501bac57 100644
--- a/target/i386/whpx-all.c
+++ b/target/i386/whpx-all.c
@@ -964,6 +964,16 @@ static int whpx_vcpu_run(CPUState *cpu)
rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
break;
+ case 0x80000001:
+ rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
+ /* Remove any support of OSVW */
+ rcx =
+ vcpu->exit_ctx.CpuidAccess.DefaultResultRcx &
+ ~CPUID_EXT3_OSVW;
+
+ rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
+ rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
+ break;
default:
rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
rcx = vcpu->exit_ctx.CpuidAccess.DefaultResultRcx;
@@ -1382,12 +1392,13 @@ static int whpx_accel_init(MachineState *ms)
goto error;
}
- UINT32 cpuidExitList[] = {1};
+ UINT32 cpuidExitList[] = {1, 0x80000001};
hr = whp_dispatch.WHvSetPartitionProperty(
whpx->partition,
WHvPartitionPropertyCodeCpuidExitList,
cpuidExitList,
RTL_NUMBER_OF(cpuidExitList) * sizeof(UINT32));
+
if (FAILED(hr)) {
error_report("WHPX: Failed to set partition CpuidExitList hr=%08lx",
hr);
--
2.13.6
- [Qemu-devel] [PATCH 1/2] WHPX workaround bug in OSVW handling,
Justin Terry (VM) <=