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@vger.kernel.org Reviewed-by: Xiaoyao Li xiaoyao.li@intel.com Signed-off-by: Chenyi Qiang chenyi.qiang@intel.com
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).
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.
Paolo