Alleviate a performance bottleneck on legacy Windows guests. In my test setup, this makes Windows XP boot times be 20x faster than they're otherwise.
Signed-off-by: Mohamed Mediouni <[email protected]> --- hw/i386/vapic.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/hw/i386/vapic.c b/hw/i386/vapic.c index 670a50524d..699f91fb56 100644 --- a/hw/i386/vapic.c +++ b/hw/i386/vapic.c @@ -16,6 +16,7 @@ #include "system/cpus.h" #include "system/hw_accel.h" #include "system/kvm.h" +#include "system/whpx.h" #include "system/runstate.h" #include "system/address-spaces.h" #include "hw/i386/apic_internal.h" @@ -229,7 +230,8 @@ static int evaluate_tpr_instruction(VAPICROMState *s, X86CPU *cpu, return -1; } - if (kvm_enabled() && !kvm_irqchip_in_kernel()) { + if ((kvm_enabled() && !kvm_irqchip_in_kernel()) + || (whpx_enabled() && !whpx_irqchip_in_kernel())) { /* * KVM without kernel-based TPR access reporting will pass an IP that * points after the accessing instruction. So we need to look backward @@ -549,7 +551,7 @@ static int patch_hypercalls(VAPICROMState *s) cpu_physical_memory_read(rom_paddr, rom, s->rom_size); for (pos = 0; pos < s->rom_size - sizeof(vmcall_pattern); pos++) { - if (kvm_irqchip_in_kernel()) { + if (kvm_enabled() && kvm_irqchip_in_kernel()) { pattern = outl_pattern; alternates[0] = outl_pattern[7]; alternates[1] = outl_pattern[7]; @@ -679,16 +681,26 @@ static void vapic_write(void *opaque, hwaddr addr, uint64_t data, } break; case 1: - if (kvm_enabled()) { + if (kvm_enabled() || (whpx_enabled() && !whpx_irqchip_in_kernel())) { /* * Disable triggering instruction in ROM by writing a NOP. * * We cannot do this in TCG mode as the reported IP is not * accurate. + * + * Oddly enough, KVM increments EIP _before_ the execution + * of the instruction is finished. */ pause_all_vcpus(); - patch_byte(cpu, env->eip - 2, 0x66); - patch_byte(cpu, env->eip - 1, 0x90); + if (!kvm_enabled()) { + patch_byte(cpu, env->eip, 0x66); + patch_byte(cpu, env->eip + 1, 0x90); + } + else { + patch_byte(cpu, env->eip - 2, 0x66); + patch_byte(cpu, env->eip - 1, 0x90); + + } resume_all_vcpus(); } @@ -705,7 +717,8 @@ static void vapic_write(void *opaque, hwaddr addr, uint64_t data, break; default: case 4: - if (!kvm_irqchip_in_kernel()) { + if ((kvm_enabled() && !kvm_irqchip_in_kernel()) + || (whpx_enabled() && !whpx_irqchip_in_kernel())) { apic_poll_irq(cpu->apic_state); } break; -- 2.50.1 (Apple Git-155)
