On Fri, Apr 20, 2012 at 04:18:47PM +0800, Xiao Guangrong wrote: > This bit indicates whether the spte is allow to be writable that > means the gpte of this spte is writable and the pfn pointed by > this spte is writable on host > > Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> > --- > arch/x86/kvm/mmu.c | 13 ++++++------- > 1 files changed, 6 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index e70ff38..dd984b6 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -145,7 +145,8 @@ module_param(dbg, bool, 0644); > #define CREATE_TRACE_POINTS > #include "mmutrace.h" > > -#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) > +#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) > +#define SPTE_ALLOW_WRITE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1)) > > #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) > > @@ -1177,9 +1178,8 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, > new_spte = *sptep & ~PT64_BASE_ADDR_MASK; > new_spte |= (u64)new_pfn << PAGE_SHIFT; > > - new_spte &= ~PT_WRITABLE_MASK; > - new_spte &= ~SPTE_HOST_WRITEABLE; > - new_spte &= ~shadow_accessed_mask; > + new_spte &= ~(PT_WRITABLE_MASK | SPTE_HOST_WRITEABLE | > + shadow_accessed_mask | SPTE_ALLOW_WRITE); Each bit should have a distinct meaning. Here the host pte is being write-protected, which means only the SPTE_HOST_WRITEABLE bit should be cleared. -- 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
