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| author | ssmith@localhost.localdomain <ssmith@localhost.localdomain> | 2006-12-11 11:16:29 -0800 |
|---|---|---|
| committer | ssmith@localhost.localdomain <ssmith@localhost.localdomain> | 2006-12-11 11:16:29 -0800 |
| commit | 7a3d8f6e4dd56771a7514624bbace26883a36da7 (patch) | |
| tree | 9d792ae7a6e4a47dc0ab56f13e7d1021360cdba1 | |
| parent | 8537fbaeade8b85d8751b2702b0b3e76dabaeff6 (diff) | |
| download | xen-7a3d8f6e4dd56771a7514624bbace26883a36da7.tar.gz xen-7a3d8f6e4dd56771a7514624bbace26883a36da7.tar.bz2 xen-7a3d8f6e4dd56771a7514624bbace26883a36da7.zip | |
[XEN] The shadow FAST_FAULT_PATH optimisation assumes that pages never
transition between mmio and RAM-backed. This isn't true after a
an add_to_physmap memory op. Fix this by just blowing the shadow tables
after every such operation; they're rare enough that the performance
hit is not a concern.
Signed-off-by: Steven Smith <sos22@cam.ac.uk>
Acked-by: Tim Deegan <Tim.Deegan@xensource.com>
| -rw-r--r-- | xen/arch/x86/mm.c | 12 | ||||
| -rw-r--r-- | xen/arch/x86/mm/shadow/common.c | 2 | ||||
| -rw-r--r-- | xen/include/asm-x86/shadow.h | 3 |
3 files changed, 15 insertions, 2 deletions
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 48dea7cffb..4c26fc9969 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -2968,7 +2968,17 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg) guest_physmap_add_page(d, xatp.gpfn, mfn); UNLOCK_BIGLOCK(d); - + + /* If we're doing FAST_FAULT_PATH, then shadow mode may have + cached the fact that this is an mmio region in the shadow + page tables. Blow the tables away to remove the cache. + This is pretty heavy handed, but this is a rare operation + (it might happen a dozen times during boot and then never + again), so it doesn't matter too much. */ + shadow_lock(d); + shadow_blow_tables(d); + shadow_unlock(d); + put_domain(d); break; diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c index 1f295758d8..b4be85ee7e 100644 --- a/xen/arch/x86/mm/shadow/common.c +++ b/xen/arch/x86/mm/shadow/common.c @@ -733,7 +733,7 @@ void shadow_prealloc(struct domain *d, unsigned int order) /* Deliberately free all the memory we can: this will tear down all of * this domain's shadows */ -static void shadow_blow_tables(struct domain *d) +void shadow_blow_tables(struct domain *d) { struct list_head *l, *t; struct shadow_page_info *sp; diff --git a/xen/include/asm-x86/shadow.h b/xen/include/asm-x86/shadow.h index 78998edea9..f923f662de 100644 --- a/xen/include/asm-x86/shadow.h +++ b/xen/include/asm-x86/shadow.h @@ -540,6 +540,9 @@ extern int shadow_remove_write_access(struct vcpu *v, mfn_t readonly_mfn, * Returns non-zero if we need to flush TLBs. */ extern int shadow_remove_all_mappings(struct vcpu *v, mfn_t target_mfn); +/* Remove all mappings from the shadows. */ +extern void shadow_blow_tables(struct domain *d); + void shadow_remove_all_shadows_and_parents(struct vcpu *v, mfn_t gmfn); /* This is a HVM page that we thing is no longer a pagetable. |