From: Wanpeng Li Date: Tue, 14 May 2019 06:06:39 +0000 (+0800) Subject: i386: Enable IA32_MISC_ENABLE MWAIT bit when exposing mwait/monitor X-Git-Tag: qemu-xen-4.13.0-rc1~147^2~19 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=4cfd7bab3f5564f6c1a23b06f73d5aa2f957cd16;p=qemu-xen.git i386: Enable IA32_MISC_ENABLE MWAIT bit when exposing mwait/monitor The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR IA32_MISC_ENABLE MWAIT bit and as userspace has control of them both, it is userspace's job to configure both bits to match on the initial setup. Cc: Eduardo Habkost Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li Message-Id: <1557813999-9175-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini --- diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 536d7d1520..c1ab86d63e 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -4730,6 +4730,9 @@ static void x86_cpu_reset(CPUState *s) env->pat = 0x0007040600070406ULL; env->msr_ia32_misc_enable = MSR_IA32_MISC_ENABLE_DEFAULT; + if (env->features[FEAT_1_ECX] & CPUID_EXT_MONITOR) { + env->msr_ia32_misc_enable |= MSR_IA32_MISC_ENABLE_MWAIT; + } memset(env->dr, 0, sizeof(env->dr)); env->dr[6] = DR6_FIXED_1; diff --git a/target/i386/cpu.h b/target/i386/cpu.h index fce6660bac..bd06523a53 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -387,6 +387,7 @@ typedef enum X86Seg { #define MSR_IA32_MISC_ENABLE 0x1a0 /* Indicates good rep/movs microcode on some processors: */ #define MSR_IA32_MISC_ENABLE_DEFAULT 1 +#define MSR_IA32_MISC_ENABLE_MWAIT (1ULL << 18) #define MSR_MTRRphysBase(reg) (0x200 + 2 * (reg)) #define MSR_MTRRphysMask(reg) (0x200 + 2 * (reg) + 1)