On 09/19/12 09:20, Eduardo Habkost wrote:
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.
Will do a V2 with a local define.
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
-Don Slutz
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