Messages in this thread Patch in this message | | | From | Avi Kivity <> | Subject | [PATCH 1/3] KVM: MMU: Store nx bit for large page shadows | Date | Tue, 17 Jul 2007 16:22:50 +0300 |
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We need to distinguish between large page shadows which have the nx bit set and those which don't. The problem shows up when booting a newer smp Linux kernel, where the trampoline page (which is in real mode, which uses the same shadow pages as large pages) is using the same mapping as a kernel data page, which is mapped using nx, causing kvm to spin on that page.
Signed-off-by: Avi Kivity <avi@qumranet.com> --- drivers/kvm/kvm.h | 4 ++-- drivers/kvm/paging_tmpl.h | 2 ++ 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index a7c5e6b..65ab268 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -121,7 +121,7 @@ struct kvm_pte_chain { * bits 4:7 - page table level for this shadow (1-4) * bits 8:9 - page table quadrant for 2-level guests * bit 16 - "metaphysical" - gfn is not a real page (huge page/real mode) - * bits 17:18 - "access" - the user and writable bits of a huge page pde + * bits 17:19 - "access" - the user, writable, and nx bits of a huge page pde */ union kvm_mmu_page_role { unsigned word; @@ -131,7 +131,7 @@ union kvm_mmu_page_role { unsigned quadrant : 2; unsigned pad_for_nice_hex_output : 6; unsigned metaphysical : 1; - unsigned hugepage_access : 2; + unsigned hugepage_access : 3; }; }; diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index a7c5cb0..4b5391c 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -366,6 +366,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, metaphysical = 1; hugepage_access = *guest_ent; hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK; + if (*guest_ent & PT64_NX_MASK) + hugepage_access |= (1 << 2); hugepage_access >>= PT_WRITABLE_SHIFT; table_gfn = (*guest_ent & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; -- 1.5.2.4 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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