From f701c082e72d4786686dfd1d9d877b64dc1d2804 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 15 May 2020 13:48:47 +0200 Subject: [PATCH] i386/kvm: correct the meaning of '0xffffffff' value for hv-spinlocks Hyper-V TLFS prior to version 6.0 had a mistake in it: special value '0xffffffff' for CPUID 0x40000004.EBX was called 'never to retry', this looked weird (like why it's not '0' which supposedly have the same effect?) but nobody raised the question. In TLFS version 6.0 the mistake was corrected to 'never notify' which sounds logical. Fix QEMU accordingly. Signed-off-by: Vitaly Kuznetsov Message-Id: <20200515114847.74523-1-vkuznets@redhat.com> Signed-off-by: Eduardo Habkost --- docs/hyperv.txt | 2 +- target/i386/cpu.c | 2 +- target/i386/cpu.h | 4 ++-- target/i386/kvm.c | 4 ++-- 4 files changed, 6 insertions(+), 6 deletions(-) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 6518b716a9..5df00da54f 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -49,7 +49,7 @@ more efficiently. In particular, this enlightenment allows paravirtualized ====================== Enables paravirtualized spinlocks. The parameter indicates how many times spinlock acquisition should be attempted before indicating the situation to the -hypervisor. A special value 0xffffffff indicates "never to retry". +hypervisor. A special value 0xffffffff indicates "never notify". 3.4. hv-vpindex ================ diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 49d8958528..37725bd354 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -7263,7 +7263,7 @@ static Property x86_cpu_properties[] = { DEFINE_PROP_BOOL("pmu", X86CPU, enable_pmu, false), DEFINE_PROP_UINT32("hv-spinlocks", X86CPU, hyperv_spinlock_attempts, - HYPERV_SPINLOCK_NEVER_RETRY), + HYPERV_SPINLOCK_NEVER_NOTIFY), DEFINE_PROP_BIT64("hv-relaxed", X86CPU, hyperv_features, HYPERV_FEAT_RELAXED, 0), DEFINE_PROP_BIT64("hv-vapic", X86CPU, hyperv_features, diff --git a/target/i386/cpu.h b/target/i386/cpu.h index d3097be6a5..f519d2bfd4 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -991,8 +991,8 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS]; #define HYPERV_FEAT_IPI 13 #define HYPERV_FEAT_STIMER_DIRECT 14 -#ifndef HYPERV_SPINLOCK_NEVER_RETRY -#define HYPERV_SPINLOCK_NEVER_RETRY 0xFFFFFFFF +#ifndef HYPERV_SPINLOCK_NEVER_NOTIFY +#define HYPERV_SPINLOCK_NEVER_NOTIFY 0xFFFFFFFF #endif #define EXCP00_DIVZ 0 diff --git a/target/i386/kvm.c b/target/i386/kvm.c index d87af57a23..9efb07e7c8 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -730,7 +730,7 @@ static bool hyperv_enabled(X86CPU *cpu) { CPUState *cs = CPU(cpu); return kvm_check_extension(cs->kvm_state, KVM_CAP_HYPERV) > 0 && - ((cpu->hyperv_spinlock_attempts != HYPERV_SPINLOCK_NEVER_RETRY) || + ((cpu->hyperv_spinlock_attempts != HYPERV_SPINLOCK_NEVER_NOTIFY) || cpu->hyperv_features || cpu->hyperv_passthrough); } @@ -1236,7 +1236,7 @@ static int hyperv_handle_properties(CPUState *cs, env->features[FEAT_HV_RECOMM_EAX] = c->eax; /* hv-spinlocks may have been overriden */ - if (cpu->hyperv_spinlock_attempts != HYPERV_SPINLOCK_NEVER_RETRY) { + if (cpu->hyperv_spinlock_attempts != HYPERV_SPINLOCK_NEVER_NOTIFY) { c->ebx = cpu->hyperv_spinlock_attempts; } }