Paolo, I'd like to test Michael's MWAIT patch on my copies of the affected OS X versions, and wanted to use kvm-kmod to build the latest KVM on my F24 box. I did:
git clone git://git.kernel.org/pub/scm/virt/kvm/kvm.git git clone https://github.com/bonzini/kvm-kmod.git cd kvm-kmod ./configure make LINUX=../kvm clean sync all Then, I get a bunch of errors: make -C /lib/modules/4.9.10-100.fc24.x86_64/build M=`pwd` clean make[1]: Entering directory '/usr/src/kernels/4.9.10-100.fc24.x86_64' make[1]: Leaving directory '/usr/src/kernels/4.9.10-100.fc24.x86_64' ./sync -v for-linus -l ../kvm make -C /lib/modules/4.9.10-100.fc24.x86_64/build M=`pwd` \ LINUXINCLUDE="-I`pwd`/include -I`pwd`/include/uapi -Iinclude \ -Iinclude2 -I/lib/modules/4.9.10-100.fc24.x86_64/source/include -I/lib/modules/4.9.10-100.fc24.x86_64/source/include/uapi -I/lib/modules/4.9.10-100.fc24.x86_64/source/arch/x86/include -I/lib/modules/4.9.10-100.fc24.x86_64/source/arch/x86/include/uapi \ -Iinclude/generated/uapi -Iarch/x86/include/generated \ -Iarch/x86/include/generated/uapi \ -I`pwd`/include-compat -I`pwd`/x86 \ -include include/generated/autoconf.h \ -include `pwd`/x86/external-module-compat.h" \ "$@" make[1]: Entering directory '/usr/src/kernels/4.9.10-100.fc24.x86_64' LD /home/somlo/FOO/kvm-kmod/x86/built-in.o CC [M] /home/somlo/FOO/kvm-kmod/x86/kvm_main.o In file included from /home/somlo/FOO/kvm-kmod/x86/external-module-compat.h:46:, from <command-line>:0: /home/somlo/FOO/kvm-kmod/x86/../external-module-compat-comm.h:1724:53: warning:struct static_key_deferred’ declared inside parameter list will not be visible outside of this definition or declaration static inline void static_key_deferred_flush(struct static_key_deferred *key) ^~~~~~~~~~~~~~~~~~~ /home/somlo/FOO/kvm-kmod/x86/../external-module-compat-comm.h: In function ‘static_key_deferred_flush’: /home/somlo/FOO/kvm-kmod/x86/../external-module-compat-comm.h:1726:25: error: dereferencing pointer to incomplete type ‘struct static_key_deferred’ flush_delayed_work(&key->work); ^~ In file included from <command-line>:0:0: /home/somlo/FOO/kvm-kmod/x86/external-module-compat.h: At top level: /home/somlo/FOO/kvm-kmod/x86/external-module-compat.h:1090:22: fatal error: asm/i387.h: No such file or directory #include <asm/i387.h> ^ compilation terminated. scripts/Makefile.build:293: recipe for target '/home/somlo/FOO/kvm-kmod/x86/kvm_main.o' failed make[3]: *** [/home/somlo/FOO/kvm-kmod/x86/kvm_main.o] Error 1 scripts/Makefile.build:544: recipe for target '/home/somlo/FOO/kvm-kmod/x86' failed make[2]: *** [/home/somlo/FOO/kvm-kmod/x86] Error 2 Makefile:1494: recipe for target '_module_/home/somlo/FOO/kvm-kmod' failed make[1]: *** [_module_/home/somlo/FOO/kvm-kmod] Error 2 make[1]: Leaving directory '/usr/src/kernels/4.9.10-100.fc24.x86_64' Makefile:21: recipe for target 'all' failed make: *** [all] Error 2 Any idea where things might be going wrong? Is F24 (4.9.10-100.fc24.x86_64) too old for this? Thanks, --Gabriel On Mon, Mar 13, 2017 at 06:19:07PM +0200, Michael S. Tsirkin wrote: > Guests running Mac OS 5, 6, and 7 (Leopard through Lion) have a problem: > unless explicitly provided with kernel command line argument > "idlehalt=0" they'd implicitly assume MONITOR and MWAIT availability, > without checking CPUID. > > We currently emulate that as a NOP but on VMX we can do better: let > guest stop the CPU until timer, IPI or memory change. CPU will be busy > but that isn't any worse than a NOP emulation. > > Note that mwait within guests is not the same as on real hardware > because halt causes an exit while mwait doesn't. For this reason it > might not be a good idea to use the regular MWAIT flag in CPUID to > signal this capability: halt is sometimes better as you are giving up > the rest of your CPU slice. Add a flag in the hypervisor leaf instead. > > Reported-by: "Gabriel L. Somlo" <gso...@gmail.com> > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > --- > > changes from v1: > - typo fix resulting in rest of leaf flags being overwritten > Reported by: Wanpeng Li <kernel...@gmail.com> > - updated commit log with data about guests helped by this feature > - better document differences between mwait and halt for guests > > > > Documentation/virtual/kvm/cpuid.txt | 3 +++ > arch/x86/include/uapi/asm/kvm_para.h | 1 + > arch/x86/kvm/cpuid.c | 3 +++ > arch/x86/kvm/vmx.c | 4 ---- > 4 files changed, 7 insertions(+), 4 deletions(-) > > diff --git a/Documentation/virtual/kvm/cpuid.txt > b/Documentation/virtual/kvm/cpuid.txt > index 3c65feb..5caa234 100644 > --- a/Documentation/virtual/kvm/cpuid.txt > +++ b/Documentation/virtual/kvm/cpuid.txt > @@ -54,6 +54,9 @@ KVM_FEATURE_PV_UNHALT || 7 || guest checks > this feature bit > || || before enabling > paravirtualized > || || spinlock support. > > ------------------------------------------------------------------------------ > +KVM_FEATURE_MWAIT || 8 || guest can use monitor/mwait > + || || to halt the VCPU. > +------------------------------------------------------------------------------ > KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no > guest-side > || || per-cpu warps are expected in > || || kvmclock. > diff --git a/arch/x86/include/uapi/asm/kvm_para.h > b/arch/x86/include/uapi/asm/kvm_para.h > index cff0bb6..9cc77a7 100644 > --- a/arch/x86/include/uapi/asm/kvm_para.h > +++ b/arch/x86/include/uapi/asm/kvm_para.h > @@ -24,6 +24,7 @@ > #define KVM_FEATURE_STEAL_TIME 5 > #define KVM_FEATURE_PV_EOI 6 > #define KVM_FEATURE_PV_UNHALT 7 > +#define KVM_FEATURE_MWAIT 8 > > /* The last 8 bits are used to indicate how to interpret the flags field > * in pvclock structure. If no bits are set, all flags are ignored. > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index efde6cc..3c7fca83 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -594,6 +594,9 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 > *entry, u32 function, > if (sched_info_on()) > entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); > > + if (this_cpu_has(X86_FEATURE_MWAIT)) > + entry->eax |= (1 << KVM_FEATURE_MWAIT); > + > entry->ebx = 0; > entry->ecx = 0; > entry->edx = 0; > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 4bfe349..b167aba 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -3547,13 +3547,9 @@ static __init int setup_vmcs_config(struct vmcs_config > *vmcs_conf) > CPU_BASED_USE_IO_BITMAPS | > CPU_BASED_MOV_DR_EXITING | > CPU_BASED_USE_TSC_OFFSETING | > - CPU_BASED_MWAIT_EXITING | > - CPU_BASED_MONITOR_EXITING | > CPU_BASED_INVLPG_EXITING | > CPU_BASED_RDPMC_EXITING; > > - printk(KERN_ERR "cleared CPU_BASED_MWAIT_EXITING + > CPU_BASED_MONITOR_EXITING\n"); > - > opt = CPU_BASED_TPR_SHADOW | > CPU_BASED_USE_MSR_BITMAPS | > CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; > -- > MST
