Am 15. Februar 2026 05:22:25 UTC schrieb Mohamed Mediouni
<[email protected]>:
>Optimise vmexits by save/restoring less state in those cases instead of the
>full state.
>
>Signed-off-by: Mohamed Mediouni <[email protected]>
>---
> target/i386/whpx/whpx-all.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
>diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
>index 7bbe63e794..9d1febce52 100644
>--- a/target/i386/whpx/whpx-all.c
>+++ b/target/i386/whpx/whpx-all.c
>@@ -420,6 +420,13 @@ void whpx_set_registers(CPUState *cpu, WHPXStateLevel
>level)
> vcxt.values[idx].Segment = whpx_seg_q2h(&env->segs[i], v86, r86);
> }
>
>+ /*
>+ * This is a hot path called on every MMIO access.
>+ */
>+ if (level <= WHPX_LEVEL_FAST_RUNTIME_STATE) {
>+ goto skip_to_set_registers;
>+ }
Looks like we can get rid of the goto by extending the scope of the if
statement to the skip_to_set_registers label.
With this fixed:
Reviewed-by: Bernhard Beschow <[email protected]>
>+
> assert(idx == WHvX64RegisterLdtr);
> vcxt.values[idx++].Segment = whpx_seg_q2h(&env->ldt, 0, 0);
>
>@@ -529,10 +536,11 @@ void whpx_set_registers(CPUState *cpu, WHPXStateLevel
>level)
>
> assert(idx == RTL_NUMBER_OF(whpx_register_names));
>
>+ skip_to_set_registers:
> hr = whp_dispatch.WHvSetVirtualProcessorRegisters(
> whpx->partition, cpu->cpu_index,
> whpx_register_names,
>- RTL_NUMBER_OF(whpx_register_names),
>+ idx,
> &vcxt.values[0]);
>
> if (FAILED(hr)) {
>@@ -612,7 +620,7 @@ void whpx_get_registers(CPUState *cpu, WHPXStateLevel
>level)
> hr);
> }
>
>- if (whpx_irqchip_in_kernel()) {
>+ if (level > WHPX_LEVEL_FAST_RUNTIME_STATE && whpx_irqchip_in_kernel()) {
> /*
> * Fetch the TPR value from the emulated APIC. It may get overwritten
> * below with the value from CR8 returned by
>@@ -668,7 +676,7 @@ void whpx_get_registers(CPUState *cpu, WHPXStateLevel
>level)
> env->cr[4] = vcxt.values[idx++].Reg64;
> assert(whpx_register_names[idx] == WHvX64RegisterCr8);
> tpr = vcxt.values[idx++].Reg64;
>- if (tpr != vcpu->tpr) {
>+ if (level > WHPX_LEVEL_FAST_RUNTIME_STATE && tpr != vcpu->tpr) {
> vcpu->tpr = tpr;
> cpu_set_apic_tpr(x86_cpu->apic_state, whpx_cr8_to_apic_tpr(tpr));
> }
>@@ -754,7 +762,7 @@ void whpx_get_registers(CPUState *cpu, WHPXStateLevel
>level)
>
> assert(idx == RTL_NUMBER_OF(whpx_register_names));
>
>- if (whpx_irqchip_in_kernel()) {
>+ if (level > WHPX_LEVEL_FAST_RUNTIME_STATE && whpx_irqchip_in_kernel()) {
> whpx_apic_get(x86_cpu->apic_state);
> }
>
