commit 0e27f3a5d0cbc0099ba8dcd7ff78e7f80d0c4f15
author Phil Dennis-Jordan <phil@philjordan.eu> Tue Nov 05 16:57:56 2024 +0100
committer Paolo Bonzini <pbonzini@redhat.com> Sat Nov 09 08:34:07 2024 +0100
tree 87ce3e63202810b2888540e51689deb04a29d7cf
parent b7e55bd9d06d193cc55d2c46bb2864d71b1db1d3

i386/hvf: Integrates x2APIC support with hvf accel

Support for x2APIC mode was recently introduced in the software emulated
APIC implementation for TCG. Enabling it when using macOS’s hvf
accelerator is useful and significantly helps performance, as Qemu
currently uses the emulated APIC when running on hvf as well.

This change wires up the read & write operations for the MSR VM exits
and allow-lists the CPUID flag in the x86 hvf runtime.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Link: https://lore.kernel.org/r/20241105155800.5461-2-phil@philjordan.eu
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/hvf/x86_cpuid.c

diff --git a/target/i386/hvf/x86_cpuid.c b/target/i386/hvf/x86_cpuid.c
index 492e8bf..3f16b0f 100644
--- a/target/i386/hvf/x86_cpuid.c
+++ b/target/i386/hvf/x86_cpuid.c
@@ -77,7 +77,7 @@
         ecx &= CPUID_EXT_SSE3 | CPUID_EXT_PCLMULQDQ | CPUID_EXT_SSSE3 |
              CPUID_EXT_FMA | CPUID_EXT_CX16 | CPUID_EXT_PCID |
              CPUID_EXT_SSE41 | CPUID_EXT_SSE42 | CPUID_EXT_MOVBE |
-             CPUID_EXT_POPCNT | CPUID_EXT_AES |
+             CPUID_EXT_POPCNT | CPUID_EXT_AES | CPUID_EXT_X2APIC |
              (supported_xcr0 ? CPUID_EXT_XSAVE : 0) |
              CPUID_EXT_AVX | CPUID_EXT_F16C | CPUID_EXT_RDRAND;
         ecx |= CPUID_EXT_HYPERVISOR;

target/i386/hvf/x86_emu.c

diff --git a/target/i386/hvf/x86_emu.c b/target/i386/hvf/x86_emu.c
index 38c782b..be675bc 100644
--- a/target/i386/hvf/x86_emu.c
+++ b/target/i386/hvf/x86_emu.c
@@ -663,6 +663,15 @@
     env->eip += decode->len;
 }
 
+static void raise_exception(CPUX86State *env, int exception_index,
+                            int error_code)
+{
+    env->exception_nr = exception_index;
+    env->error_code = error_code;
+    env->has_error_code = true;
+    env->exception_injected = 1;
+}
+
 void simulate_rdmsr(CPUX86State *env)
 {
     X86CPU *cpu = env_archcpu(env);
@@ -677,6 +686,17 @@
     case MSR_IA32_APICBASE:
         val = cpu_get_apic_base(cpu->apic_state);
         break;
+    case MSR_APIC_START ... MSR_APIC_END: {
+        int ret;
+        int index = (uint32_t)env->regs[R_ECX] - MSR_APIC_START;
+
+        ret = apic_msr_read(index, &val);
+        if (ret < 0) {
+            raise_exception(env, EXCP0D_GPF, 0);
+        }
+
+        break;
+    }
     case MSR_IA32_UCODE_REV:
         val = cpu->ucode_rev;
         break;
@@ -777,6 +797,17 @@
     case MSR_IA32_APICBASE:
         cpu_set_apic_base(cpu->apic_state, data);
         break;
+    case MSR_APIC_START ... MSR_APIC_END: {
+        int ret;
+        int index = (uint32_t)env->regs[R_ECX] - MSR_APIC_START;
+
+        ret = apic_msr_write(index, data);
+        if (ret < 0) {
+            raise_exception(env, EXCP0D_GPF, 0);
+        }
+
+        break;
+    }
     case MSR_FSBASE:
         wvmcs(cs->accel->fd, VMCS_GUEST_FS_BASE, data);
         break;