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Commit 59151001 authored by Stefano Stabellini's avatar Stefano Stabellini Committed by Jeremy Fitzhardinge
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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: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
parent c1c5413a
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+1 −0
Original line number Diff line number Diff line
@@ -1318,6 +1318,7 @@ static void __init xen_hvm_guest_init(void)
	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)
+33 −0
Original line number Diff line number Diff line
@@ -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 @@ void __init xen_init_mmu_ops(void)
	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;
+1 −0
Original line number Diff line number Diff line
@@ -60,4 +60,5 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
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 */
+11 −0
Original line number Diff line number Diff line
@@ -32,4 +32,15 @@ struct xen_hvm_param {
};
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__ */