Re: [PATCH 4/6] kvm/x86/mmu: handle invlpg on large pages

From: Marcelo Tosatti
Date: Thu Mar 05 2009 - 16:18:20 EST


On Thu, Mar 05, 2009 at 01:12:31PM +0100, Joerg Roedel wrote:
> Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
> ---
> arch/x86/kvm/paging_tmpl.h | 12 +++++++++---
> 1 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
> index 79668ba..aa79396 100644
> --- a/arch/x86/kvm/paging_tmpl.h
> +++ b/arch/x86/kvm/paging_tmpl.h
> @@ -441,6 +441,7 @@ out_unlock:
> static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
> {
> struct kvm_shadow_walk_iterator iterator;
> + struct kvm_mmu_page *sp;
> pt_element_t gpte;
> gpa_t pte_gpa = -1;
> int level;
> @@ -451,12 +452,17 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
> for_each_shadow_entry(vcpu, gva, iterator) {
> level = iterator.level;
> sptep = iterator.sptep;
> + sp = page_header(__pa(sptep));
> +
> + if (sp->role.direct) {
> + /* mapped from a guest's large_pte */
> + kvm_mmu_zap_page(vcpu->kvm, sp);
> + kvm_flush_remote_tlbs(vcpu->kvm);
> + return;
> + }

If the guest has 32-bit pte's there might be:

- two large shadow entries to cover 4MB
- one large shadow entry and one shadow page with 512 4k entries
- two shadow pages with 512 4k entries each

So need to cover all this cases.

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