On Tue, Sep 18, 2012 at 03:32:04PM -0400, Don Slutz wrote: > On 09/18/12 13:00, Eduardo Habkost wrote: > >On Tue, Sep 18, 2012 at 10:49:53AM -0400, Don Slutz wrote: > >> From http://lkml.indiana.edu/hypermail/linux/kernel/1205.0/00100.html > >>EAX should be KVM_CPUID_FEATURES (0x40000001) not 0. > >> > >>If kvm is not configured, the additional option of hypervisor-level=1 > >>(or hypervisor-level=0x40000001) needs to be specified to get this. > >>--- > >> target-i386/cpu.c | 12 +++++++++++- > >> 1 files changed, 11 insertions(+), 1 deletions(-) > >> > >>diff --git a/target-i386/cpu.c b/target-i386/cpu.c > >>index 6e43eff..d73b0a8 100644 > >>--- a/target-i386/cpu.c > >>+++ b/target-i386/cpu.c > >>@@ -1248,7 +1248,12 @@ static char *x86_cpuid_get_hv_vendor(Object *obj, Error **errp) > >> env->cpuid_hv_level == CPUID_HV_LEVEL_XEN) { > >> pstrcpy(value, sizeof(value), "xen"); > >> } else if (!strcmp(value, CPUID_HV_VENDOR_KVM) && > >>- env->cpuid_hv_level == 0) { > >>+#if defined(CONFIG_KVM) > >>+ env->cpuid_hv_level == KVM_CPUID_FEATURES > >>+#else > >>+ env->cpuid_hv_level == 0 > >>+#endif > >>+ ) { > >> pstrcpy(value, sizeof(value), "kvm"); > >> } > >> return value; > >>@@ -1281,6 +1286,11 @@ static void x86_cpuid_set_hv_vendor(Object *obj, const char *value, > >> } > >> pstrcpy(adj_value, sizeof(adj_value), CPUID_HV_VENDOR_XEN); > >> } else if (!strcmp(value, "kvm")) { > >>+#if defined(CONFIG_KVM) > >>+ if (env->cpuid_hv_level == 0) { > >>+ env->cpuid_hv_level = KVM_CPUID_FEATURES; > >>+ } > >>+#endif > >If CPUID[0x40000000].EAX set to 0 is documented as equivalent to having > >it set to 0x40000001 (KVM_CPUID_FEATURES), why the confusing checks for > >CONFIG_KVM? Why not always set it to KVM_CPUID_FEATURES? > > > At line 36 of the file: > > #if defined(CONFIG_KVM) > #include <linux/kvm_para.h> > #endif > > So without the check you get compile failures (i386-linux-user). > Right. We can't include linux/kvm_para.h on a non-Linux build host, but on the other hand I don't see any reason to not have cpuid_hv_level=0x40000001 on builds without CONFIG_KVM too. If we want to allow fake KVM CPUID leaves on non-CONFIG_KVM builds like the code above does, QEMU needs its own constant for KVM_CPUID_FEATURES/0x40000001, so it doesn't depend on the Linux header. > I have no issue with removing the check(s) for 0. Currently > hypervisor-level=0 will not force the old values; I can make a change > so that works. > -Don Slutz -- Eduardo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
