Commit d2d6d91794 for qemu.org

commit d2d6d917949d67435c29f866f26259c00597e6ad
Author: Mohamed Mediouni <mohamed@unpredictable.fr>
Date:   Tue Mar 24 16:13:13 2026 +0100

    whpx: i386: enable exceptions VM exit only when needed

    The exceptions VM exit was enabled with an empty bitmask
    even when not used.

    Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
    Link: https://lore.kernel.org/r/20260324151323.74473-3-mohamed@unpredictable.fr
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index 015c0f1dc9..8f1835ee95 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -903,13 +903,31 @@ static void whpx_init_emu(void)
 HRESULT whpx_set_exception_exit_bitmap(UINT64 exceptions)
 {
     struct whpx_state *whpx = &whpx_global;
-    WHV_PARTITION_PROPERTY prop = { 0, };
+    WHV_PARTITION_PROPERTY prop;
     HRESULT hr;

     if (exceptions == whpx->exception_exit_bitmap) {
         return S_OK;
     }

+    /* Register for MSR and CPUID exits */
+    memset(&prop, 0, sizeof(WHV_PARTITION_PROPERTY));
+    prop.ExtendedVmExits.X64MsrExit = 1;
+    if (exceptions != 0) {
+        prop.ExtendedVmExits.ExceptionExit = 1;
+    }
+
+    hr = whp_dispatch.WHvSetPartitionProperty(
+            whpx->partition,
+            WHvPartitionPropertyCodeExtendedVmExits,
+            &prop,
+            sizeof(WHV_PARTITION_PROPERTY));
+    if (FAILED(hr)) {
+        error_report("WHPX: Failed to enable extended VM exits, hr=%08lx", hr);
+        return hr;
+    }
+
+    memset(&prop, 0, sizeof(WHV_PARTITION_PROPERTY));
     prop.ExceptionExitBitmap = exceptions;

     hr = whp_dispatch.WHvSetPartitionProperty(
@@ -2167,7 +2185,6 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
     /* Register for MSR and CPUID exits */
     memset(&prop, 0, sizeof(WHV_PARTITION_PROPERTY));
     prop.ExtendedVmExits.X64MsrExit = 1;
-    prop.ExtendedVmExits.ExceptionExit = 1;

     hr = whp_dispatch.WHvSetPartitionProperty(
             whpx->partition,
@@ -2175,7 +2192,7 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
             &prop,
             sizeof(WHV_PARTITION_PROPERTY));
     if (FAILED(hr)) {
-        error_report("WHPX: Failed to enable MSR & CPUIDexit, hr=%08lx", hr);
+        error_report("WHPX: Failed to enable extended VM exits, hr=%08lx", hr);
         ret = -EINVAL;
         goto error;
     }