Messages in this thread | | | Date | Sat, 14 Apr 2012 12:01:53 +0900 | From | Takuya Yoshikawa <> | Subject | Re: [PATCH v2 10/16] KVM: MMU: fask check whether page is writable |
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On Fri, 13 Apr 2012 18:14:26 +0800 Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> wrote:
> Using bit 1 (PTE_LIST_WP_BIT) in rmap store the write-protect status > to avoid unnecessary shadow page walking > > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > --- > arch/x86/kvm/mmu.c | 40 ++++++++++++++++++++++++++++++++++------ > 1 files changed, 34 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 0c6e92d..8b71908 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -796,7 +796,9 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn) > return level - 1; > } > > -#define PTE_LIST_DESC (0x1ull) > +#define PTE_LIST_DESC_BIT 0 > +#define PTE_LIST_WP_BIT 1
_BIT ?
> +#define PTE_LIST_DESC (1 << PTE_LIST_DESC_BIT) > #define PTE_LIST_FLAG_MASK (0x3ull) >
Well, I think that rmap is losing its original meaning: Before, it held just the information needed to link spteps.
Now it has more roles, and getting kind of descriptor?
...
> @@ -2291,9 +2310,15 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, > { > struct kvm_mmu_page *s; > struct hlist_node *node; > + unsigned long *rmap; > bool need_unsync = false; > > + rmap = gfn_to_rmap(vcpu->kvm, gfn, PT_PAGE_TABLE_LEVEL);
Please use consistent variable names.
In other parts of this patch, you are using rmapp for this.
Takuya
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