On 11/5/2019 9:03 PM, Paolo Bonzini wrote:
On 05/11/19 13:51, Xiaoyao Li wrote:
On 11/5/2019 7:30 PM, Paolo Bonzini wrote:
On 05/11/19 10:20, Chenyi Qiang wrote:
The three msr number lists(msrs_to_save[], emulated_msrs[] and
msr_based_features[]) are global arrays of kvm.ko, which are
initialized/adjusted (copy supported MSRs forward to override the
unsupported MSRs) when installing kvm-{intel,amd}.ko, but it doesn't
reset these three arrays to their initial value when uninstalling
kvm-{intel,amd}.ko. Thus, at the next installation, kvm-{intel,amd}.ko
will initialize the modified arrays with some MSRs lost and some MSRs
duplicated.
So allocate and initialize these three MSR number lists dynamically when
installing kvm-{intel,amd}.ko and free them when uninstalling.
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Chenyi Qiang <chenyi.qiang@xxxxxxxxx>
---
arch/x86/kvm/x86.c | 86 ++++++++++++++++++++++++++++++----------------
1 file changed, 57 insertions(+), 29 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ff395f812719..08efcf6351cc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1132,13 +1132,15 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc);
* List of msr numbers which we expose to userspace through
KVM_GET_MSRS
* and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
*
- * This list is modified at module load time to reflect the
+ * The three msr number lists(msrs_to_save, emulated_msrs,
msr_based_features)
+ * are allocated and initialized at module load time and freed at
unload time.
+ * msrs_to_save is selected from the msrs_to_save_all to reflect the
* capabilities of the host cpu. This capabilities test skips MSRs
that are
- * kvm-specific. Those are put in emulated_msrs; filtering of
emulated_msrs
+ * kvm-specific. Those are put in emulated_msrs_all; filtering of
emulated_msrs
* may depend on host virtualization features rather than host cpu
features.
*/
-static u32 msrs_to_save[] = {
+const u32 msrs_to_save_all[] = {
This can remain static.
How about static const u32 msrs_to_save_all[] ?
Or you think static is enough?
"static const" is best indeed (that's what I meant, but I wasn't very
clear).
Yes, considering the read-only property and scope of these arrays,
"static const" is more accurate. Thanks.
Paolo
MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP,
MSR_IA32_SYSENTER_EIP,
MSR_STAR,
#ifdef CONFIG_X86_64
@@ -1179,9 +1181,10 @@ static u32 msrs_to_save[] = {
MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
};
+static u32 *msrs_to_save;
You can use ARRAY_SIZE to allocate the destination arrays statically.
It's much better, then we don't need to allocation and free.
Got it. Thanks!
Paolo
