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From: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Cc: akpm-3NddpPZAyC0@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [PATCH 31/33] KVM: MMU: Flush guest tlb when reducing permissions on	a pte
Date: Thu, 04 Jan 2007 16:20:07 -0000	[thread overview]
Message-ID: <20070104162007.AF4E9250048@il.qumranet.com> (raw)
In-Reply-To: <459D21DD.5090506-atKUWr5tajBWk0Htik3J/w@public.gmane.org>

If we reduce permissions on a pte, we must flush the cached copy of the pte
from the guest's tlb.

This is implemented at the moment by flushing the entire guest tlb, and can
be improved by flushing just the relevant virtual address, if it is known.

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>

Index: linux-2.6/drivers/kvm/mmu.c
===================================================================
--- linux-2.6.orig/drivers/kvm/mmu.c
+++ linux-2.6/drivers/kvm/mmu.c
@@ -383,6 +383,7 @@ static void rmap_write_protect(struct kv
 		BUG_ON(!(*spte & PT_WRITABLE_MASK));
 		rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
 		rmap_remove(vcpu, spte);
+		kvm_arch_ops->tlb_flush(vcpu);
 		*spte &= ~(u64)PT_WRITABLE_MASK;
 	}
 }
@@ -594,6 +595,7 @@ static void kvm_mmu_page_unlink_children
 				rmap_remove(vcpu, &pt[i]);
 			pt[i] = 0;
 		}
+		kvm_arch_ops->tlb_flush(vcpu);
 		return;
 	}
 
@@ -927,7 +929,10 @@ static inline void set_pte_common(struct
 			pgprintk("%s: found shadow page for %lx, marking ro\n",
 				 __FUNCTION__, gfn);
 			access_bits &= ~PT_WRITABLE_MASK;
-			*shadow_pte &= ~PT_WRITABLE_MASK;
+			if (is_writeble_pte(*shadow_pte)) {
+				    *shadow_pte &= ~PT_WRITABLE_MASK;
+				    kvm_arch_ops->tlb_flush(vcpu);
+			}
 		}
 	}
 

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  parent reply	other threads:[~2007-01-04 16:20 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-04 15:48 [PATCH 0/33] KVM: MMU: Cache shadow page tables Avi Kivity
2007-01-04 15:50 ` [PATCH 1/33] KVM: MMU: Implement simple reverse mapping Avi Kivity
2007-01-04 16:05 ` [PATCH 16/33] KVM: MMU: kvm_mmu_put_page() only removes one link to the page Avi Kivity
     [not found] ` <459D21DD.5090506-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-01-04 15:51   ` [PATCH 2/33] KVM: MMU: Teach the page table walker to track guest page table gfns Avi Kivity
2007-01-04 15:52   ` [PATCH 3/33] KVM: MMU: Load the pae pdptrs on cr3 change like the processor does Avi Kivity
2007-01-04 15:53   ` [PATCH 4/33] KVM: MMU: Fold fetch_guest() into init_walker() Avi Kivity
2007-01-04 15:54   ` [PATCH 5/33] KVM: MU: Special treatment for shadow pae root pages Avi Kivity
2007-01-04 15:55   ` [PATCH 6/33] KVM: MMU: Use the guest pdptrs instead of mapping cr3 in pae mode Avi Kivity
2007-01-04 15:56   ` [PATCH 7/33] KVM: MMU: Make the shadow page tables also special-case pae Avi Kivity
2007-01-04 15:57   ` [PATCH 8/33] KVM: MMU: Make kvm_mmu_alloc_page() return a kvm_mmu_page pointer Avi Kivity
2007-01-04 15:58   ` [PATCH 9/33] KVM: MMU: Shadow page table caching Avi Kivity
2007-01-04 15:59   ` [PATCH 10/33] KVM: MMU: Write protect guest pages when a shadow is created for them Avi Kivity
2007-01-04 16:00   ` [PATCH 11/33] KVM: MMU: Let the walker extract the target page gfn from the pte Avi Kivity
2007-01-04 16:01   ` [PATCH 12/33] KVM: MMU: Support emulated writes into RAM Avi Kivity
2007-01-04 16:02   ` [PATCH 13/33] KVM: MMU: Zap shadow page table entries on writes to guest page tables Avi Kivity
2007-01-04 16:03   ` [PATCH 14/33] KVM: MMU: If emulating an instruction fails, try unprotecting the page Avi Kivity
2007-01-04 16:04   ` [PATCH 15/33] KVM: MMU: Implement child shadow unlinking Avi Kivity
2007-01-04 16:06   ` [PATCH 17/33] KVM: MMU: oom handling Avi Kivity
2007-01-04 16:07   ` [PATCH 18/33] KVM: MMU: Remove invlpg interception Avi Kivity
2007-01-04 16:08   ` [PATCH 19/33] KVM: MMU: Remove release_pt_page_64() Avi Kivity
2007-01-04 16:10   ` [PATCH 21/33] KVM: MMU: <ove is_empty_shadow_page() above kvm_mmu_free_page() Avi Kivity
2007-01-04 16:11   ` [PATCH 22/33] KVM: MMU: Ensure freed shadow pages are clean Avi Kivity
2007-01-04 16:13   ` [PATCH 24/33] KVM: MMU: Page table write flood protection Avi Kivity
2007-01-04 16:14   ` [PATCH 25/33] KVM: MMU: Never free a shadow page actively serving as a root Avi Kivity
2007-01-04 16:15   ` [PATCH 26/33] KVM: MMU: Fix cmpxchg8b emulation Avi Kivity
2007-01-04 16:16   ` [PATCH 27/33] KVM: MMU: Treat user-mode faults as a hint that a page is no longer a page table Avi Kivity
2007-01-04 16:17   ` [PATCH 28/33] KVM: MMU: Free pages on kvm destruction Avi Kivity
2007-01-04 16:18   ` [PATCH 29/33] KVM: MMU: Replace atomic allocations by preallocated objects Avi Kivity
2007-01-04 16:19   ` [PATCH 30/33] KVM: MMU: Detect oom conditions and propagate error to userspace Avi Kivity
2007-01-04 16:20   ` Avi Kivity [this message]
2007-01-04 16:21   ` [PATCH 32/33] KVM: MMU: Destroy mmu while we still have a vcpu left Avi Kivity
2007-01-04 16:22   ` [PATCH 33/33] KVM: MMU: add audit code to check mappings, etc are correct Avi Kivity
2007-01-04 17:22   ` [PATCH 0/33] KVM: MMU: Cache shadow page tables Andrew Morton
     [not found]     ` <20070104092226.91fa2dfe.akpm-3NddpPZAyC0@public.gmane.org>
2007-01-04 17:41       ` Avi Kivity
     [not found]         ` <459D3C65.2090703-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-01-04 18:02           ` Ingo Molnar
2007-01-04 16:09 ` [PATCH 20/33] KVM: MMU: Handle misaligned accesses to write protected guest " Avi Kivity
2007-01-04 16:12 ` [PATCH 23/33] KVM: MMU: If an empty shadow page is not empty, report more info Avi Kivity

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