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-rw-r--r--arch/x86/xen/enlighten.c13
-rw-r--r--arch/x86/xen/mmu.c21
-rw-r--r--arch/x86/xen/mmu.h4
-rw-r--r--include/xen/interface/features.h3
-rw-r--r--include/xen/interface/xen.h9
5 files changed, 45 insertions, 5 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0b7553cbc52..bd74229081c 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -168,7 +168,9 @@ static void __init xen_banner(void)
{
printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
pv_info.name);
- printk(KERN_INFO "Hypervisor signature: %s\n", xen_start_info->magic);
+ printk(KERN_INFO "Hypervisor signature: %s%s\n",
+ xen_start_info->magic,
+ xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
}
static void xen_cpuid(unsigned int *ax, unsigned int *bx,
@@ -1243,6 +1245,8 @@ asmlinkage void __init xen_start_kernel(void)
BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
+ xen_setup_features();
+
/* Install Xen paravirt ops */
pv_info = xen_info;
pv_init_ops = xen_init_ops;
@@ -1252,14 +1256,17 @@ asmlinkage void __init xen_start_kernel(void)
pv_apic_ops = xen_apic_ops;
pv_mmu_ops = xen_mmu_ops;
+ if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
+ pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
+ pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
+ }
+
machine_ops = xen_machine_ops;
#ifdef CONFIG_SMP
smp_ops = xen_smp_ops;
#endif
- xen_setup_features();
-
/* Get mfn list */
if (!xen_feature(XENFEAT_auto_translated_physmap))
xen_build_dynamic_phys_to_machine();
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 8132aa8c5d4..846dad7d54a 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -323,6 +323,27 @@ out:
preempt_enable();
}
+pte_t xen_ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ /* Just return the pte as-is. We preserve the bits on commit */
+ return *ptep;
+}
+
+void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ struct multicall_space mcs;
+ struct mmu_update *u;
+
+ mcs = xen_mc_entry(sizeof(*u));
+ u = mcs.args;
+ u->ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
+ u->val = pte_val_ma(pte);
+ MULTI_mmu_update(mcs.mc, u, 1, NULL, DOMID_SELF);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+}
+
/* Assume pteval_t is equivalent to all the other *val_t types. */
static pteval_t pte_mfn_to_pfn(pteval_t val)
{
diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h
index e3dd09e25c6..297bf9f5b8b 100644
--- a/arch/x86/xen/mmu.h
+++ b/arch/x86/xen/mmu.h
@@ -52,4 +52,8 @@ void xen_set_pud_hyper(pud_t *ptr, pud_t val);
void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
void xen_pmd_clear(pmd_t *pmdp);
+pte_t xen_ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte);
+
#endif /* _XEN_MMU_H */
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index d73228d1648..f51b6413b05 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -38,6 +38,9 @@
*/
#define XENFEAT_pae_pgdir_above_4gb 4
+/* x86: Does this Xen host support the MMU_PT_UPDATE_PRESERVE_AD hypercall? */
+#define XENFEAT_mmu_pt_update_preserve_ad 5
+
#define XENFEAT_NR_SUBMAPS 1
#endif /* __XEN_PUBLIC_FEATURES_H__ */
diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
index 819a0331cda..2befa3e2f1b 100644
--- a/include/xen/interface/xen.h
+++ b/include/xen/interface/xen.h
@@ -114,9 +114,14 @@
* ptr[:2] -- Machine address within the frame whose mapping to modify.
* The frame must belong to the FD, if one is specified.
* val -- Value to write into the mapping entry.
+ *
+ * ptr[1:0] == MMU_PT_UPDATE_PRESERVE_AD:
+ * As MMU_NORMAL_PT_UPDATE above, but A/D bits currently in the PTE are ORed
+ * with those in @val.
*/
-#define MMU_NORMAL_PT_UPDATE 0 /* checked '*ptr = val'. ptr is MA. */
-#define MMU_MACHPHYS_UPDATE 1 /* ptr = MA of frame to modify entry for */
+#define MMU_NORMAL_PT_UPDATE 0 /* checked '*ptr = val'. ptr is MA. */
+#define MMU_MACHPHYS_UPDATE 1 /* ptr = MA of frame to modify entry for */
+#define MMU_PT_UPDATE_PRESERVE_AD 2 /* atomically: *ptr = val | (*ptr&(A|D)) */
/*
* MMU EXTENDED OPERATIONS