x86: Call HVMOP_pagetable_dying on exit_mmap.
When a pagetable is about to be destroyed, we notify Xen so that the
hypervisor can clear the related shadow pagetable.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 157c93b..75b479a 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1318,6 +1318,7 @@
have_vcpu_info_placement = 0;
x86_init.irqs.intr_init = xen_init_IRQ;
xen_hvm_init_time_ops();
+ xen_hvm_init_mmu_ops();
}
static bool __init xen_hvm_platform(void)
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 914f046..84648c1 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -58,6 +58,7 @@
#include <xen/page.h>
#include <xen/interface/xen.h>
+#include <xen/interface/hvm/hvm_op.h>
#include <xen/interface/version.h>
#include <xen/hvc-console.h>
@@ -1941,6 +1942,38 @@
pv_mmu_ops = xen_mmu_ops;
}
+static void xen_hvm_exit_mmap(struct mm_struct *mm)
+{
+ struct xen_hvm_pagetable_dying a;
+ int rc;
+
+ a.domid = DOMID_SELF;
+ a.gpa = __pa(mm->pgd);
+ rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a);
+ WARN_ON_ONCE(rc < 0);
+}
+
+static int is_pagetable_dying_supported(void)
+{
+ struct xen_hvm_pagetable_dying a;
+ int rc = 0;
+
+ a.domid = DOMID_SELF;
+ a.gpa = 0x00;
+ rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a);
+ if (rc < 0) {
+ printk(KERN_DEBUG "HVMOP_pagetable_dying not supported\n");
+ return 0;
+ }
+ return 1;
+}
+
+void __init xen_hvm_init_mmu_ops(void)
+{
+ if (is_pagetable_dying_supported())
+ pv_mmu_ops.exit_mmap = xen_hvm_exit_mmap;
+}
+
#ifdef CONFIG_XEN_DEBUG_FS
static struct dentry *d_mmu_debug;
diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h
index 5fe6bc7..fa938c4 100644
--- a/arch/x86/xen/mmu.h
+++ b/arch/x86/xen/mmu.h
@@ -60,4 +60,5 @@
unsigned long xen_read_cr2_direct(void);
extern void xen_init_mmu_ops(void);
+extern void xen_hvm_init_mmu_ops(void);
#endif /* _XEN_MMU_H */
diff --git a/include/xen/interface/hvm/hvm_op.h b/include/xen/interface/hvm/hvm_op.h
index 73c8c7e..a4827f4 100644
--- a/include/xen/interface/hvm/hvm_op.h
+++ b/include/xen/interface/hvm/hvm_op.h
@@ -32,4 +32,15 @@
};
DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_param);
+/* Hint from PV drivers for pagetable destruction. */
+#define HVMOP_pagetable_dying 9
+struct xen_hvm_pagetable_dying {
+ /* Domain with a pagetable about to be destroyed. */
+ domid_t domid;
+ /* guest physical address of the toplevel pagetable dying */
+ aligned_u64 gpa;
+};
+typedef struct xen_hvm_pagetable_dying xen_hvm_pagetable_dying_t;
+DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_pagetable_dying_t);
+
#endif /* __XEN_PUBLIC_HVM_HVM_OP_H__ */