Re: [PATCH v5 2/9] KVM: MMU: fix race between 'walk_addr' and 'fetch'

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 07/11/2010 03:52 PM, Avi Kivity wrote:
On 07/06/2010 01:45 PM, Xiao Guangrong wrote:
'walk_addr' is out of mmu_lock's protection, so while we handle 'fetch',
then guest's mapping has modifited by other vcpu's write path, such as
invlpg, pte_write and other fetch path

Fixed by checking all level's mapping


@@ -319,22 +319,23 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
          direct_access&= ~ACC_WRITE_MASK;

      for_each_shadow_entry(vcpu, addr, iterator) {
+        bool nonpresent = false, last_mapping = false;
+

I don't like these two new variables, but no suggestion at the moment. I'll try to simplify this loop later.

One idea may be:

   while (level > walker.level) {
         handle indirect pages
   }
   while (level > hlevel) {
         handle direct pages
   }
   handle last spte

I'm worried that this change is too big for backporting, but no suggestions on how to make it smaller, so we'll have to accept it.

Okay, I couldn't resist, posting this soon.

--
error compiling committee.c: too many arguments to function

--
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


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux