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authorAnton Arapov <anton@redhat.com>2012-10-29 11:15:37 +0100
committerAnton Arapov <anton@redhat.com>2012-10-29 11:15:37 +0100
commit7d558cd9c7b18e4b16953265aa0da45e63f3b968 (patch)
tree7135d5a810768c9c619346282ee9cfdf1765e225 /arch/x86/xen/mmu.c
parent985ef6b2108ed28ffd5f6630e1e0fce2e2a775f2 (diff)
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fedora kernel: cd394142aac30b5c751f25b517572e2448695641v3.6.3-2f17
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/x86/xen/mmu.c')
-rw-r--r--arch/x86/xen/mmu.c51
1 files changed, 39 insertions, 12 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 3a73785631c..5141d808e75 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -308,8 +308,20 @@ static bool xen_batched_set_pte(pte_t *ptep, pte_t pteval)
static inline void __xen_set_pte(pte_t *ptep, pte_t pteval)
{
- if (!xen_batched_set_pte(ptep, pteval))
- native_set_pte(ptep, pteval);
+ if (!xen_batched_set_pte(ptep, pteval)) {
+ /*
+ * Could call native_set_pte() here and trap and
+ * emulate the PTE write but with 32-bit guests this
+ * needs two traps (one for each of the two 32-bit
+ * words in the PTE) so do one hypercall directly
+ * instead.
+ */
+ struct mmu_update u;
+
+ u.ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE;
+ u.val = pte_val_ma(pteval);
+ HYPERVISOR_mmu_update(&u, 1, NULL, DOMID_SELF);
+ }
}
static void xen_set_pte(pte_t *ptep, pte_t pteval)
@@ -1244,7 +1256,8 @@ static void xen_flush_tlb_single(unsigned long addr)
}
static void xen_flush_tlb_others(const struct cpumask *cpus,
- struct mm_struct *mm, unsigned long va)
+ struct mm_struct *mm, unsigned long start,
+ unsigned long end)
{
struct {
struct mmuext_op op;
@@ -1256,7 +1269,7 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
} *args;
struct multicall_space mcs;
- trace_xen_mmu_flush_tlb_others(cpus, mm, va);
+ trace_xen_mmu_flush_tlb_others(cpus, mm, start, end);
if (cpumask_empty(cpus))
return; /* nothing to do */
@@ -1269,11 +1282,10 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
- if (va == TLB_FLUSH_ALL) {
- args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
- } else {
+ args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
+ if (end != TLB_FLUSH_ALL && (end - start) <= PAGE_SIZE) {
args->op.cmd = MMUEXT_INVLPG_MULTI;
- args->op.arg1.linear_addr = va;
+ args->op.arg1.linear_addr = start;
}
MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
@@ -1416,13 +1428,28 @@ static pte_t __init mask_rw_pte(pte_t *ptep, pte_t pte)
}
#endif /* CONFIG_X86_64 */
-/* Init-time set_pte while constructing initial pagetables, which
- doesn't allow RO pagetable pages to be remapped RW */
+/*
+ * Init-time set_pte while constructing initial pagetables, which
+ * doesn't allow RO page table pages to be remapped RW.
+ *
+ * If there is no MFN for this PFN then this page is initially
+ * ballooned out so clear the PTE (as in decrease_reservation() in
+ * drivers/xen/balloon.c).
+ *
+ * Many of these PTE updates are done on unpinned and writable pages
+ * and doing a hypercall for these is unnecessary and expensive. At
+ * this point it is not possible to tell if a page is pinned or not,
+ * so always write the PTE directly and rely on Xen trapping and
+ * emulating any updates as necessary.
+ */
static void __init xen_set_pte_init(pte_t *ptep, pte_t pte)
{
- pte = mask_rw_pte(ptep, pte);
+ if (pte_mfn(pte) != INVALID_P2M_ENTRY)
+ pte = mask_rw_pte(ptep, pte);
+ else
+ pte = __pte_ma(0);
- xen_set_pte(ptep, pte);
+ native_set_pte(ptep, pte);
}
static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)