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x86/shadow: sh_{make,destroy}_monitor_table() are "even more" HVM-only

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With them depending on just the number of shadow levels, there's no need
for more than one instance of them, and hence no need for any hook (IOW
452219e246 ["x86/shadow: monitor table is HVM-only"] didn't go quite
far enough). Move the functions to hvm.c while dropping the dead
is_pv_32bit_domain() code paths.

While moving the code, replace a stale comment reference to
sh_install_xen_entries_in_l4(). Doing so made me notice the function
also didn't have its prototype dropped in 8d7b633ada ("x86/mm:
Consolidate all Xen L4 slot writing into init_xen_l4_slots()"), which
gets done here as well.

Also make their first parameters const.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
This commit is contained in:
Jan Beulich committed 2020-10-30 14:26:46 +01:00
1 parent 8ac7e452a6
commit 0b841314da
6 files changed
+100 -142
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xen/arch/x86/mm/shadow/common.c
+10 -4
View File
@@ -2467,7 +2467,9 @@ static void sh_update_paging_modes(struct vcpu *v)
if ( pagetable_is_null(v->arch.hvm.monitor_table) )
{
mfn_t mmfn = v->arch.paging.mode->shadow.make_monitor_table(v);
mfn_t mmfn = sh_make_monitor_table(
v, v->arch.paging.mode->shadow.shadow_levels);
v->arch.hvm.monitor_table = pagetable_from_mfn(mmfn);
make_cr3(v, mmfn);
hvm_update_host_cr3(v);
@@ -2504,7 +2506,8 @@ static void sh_update_paging_modes(struct vcpu *v)
old_mfn = pagetable_get_mfn(v->arch.hvm.monitor_table);
v->arch.hvm.monitor_table = pagetable_null();
new_mfn = v->arch.paging.mode->shadow.make_monitor_table(v);
new_mfn = sh_make_monitor_table(
v, v->arch.paging.mode->shadow.shadow_levels);
v->arch.hvm.monitor_table = pagetable_from_mfn(new_mfn);
SHADOW_PRINTK("new monitor table %"PRI_mfn "\n",
mfn_x(new_mfn));
@@ -2516,7 +2519,8 @@ static void sh_update_paging_modes(struct vcpu *v)
if ( v == current )
write_ptbase(v);
hvm_update_host_cr3(v);
old_mode->shadow.destroy_monitor_table(v, old_mfn);
sh_destroy_monitor_table(v, old_mfn,
old_mode->shadow.shadow_levels);
}
}
@@ -2801,7 +2805,9 @@ void shadow_teardown(struct domain *d, bool *preempted)
mfn_t mfn = pagetable_get_mfn(v->arch.hvm.monitor_table);
if ( mfn_valid(mfn) && (mfn_x(mfn) != 0) )
v->arch.paging.mode->shadow.destroy_monitor_table(v, mfn);
sh_destroy_monitor_table(
v, mfn,
v->arch.paging.mode->shadow.shadow_levels);
v->arch.hvm.monitor_table = pagetable_null();
}
#endif /* CONFIG_HVM */
xen/arch/x86/mm/shadow/hvm.c
+82
View File
@@ -691,6 +691,88 @@ static void sh_emulate_unmap_dest(struct vcpu *v, void *addr,
atomic_inc(&v->domain->arch.paging.shadow.gtable_dirty_version);
}
mfn_t sh_make_monitor_table(const struct vcpu *v, unsigned int shadow_levels)
{
struct domain *d = v->domain;
mfn_t m4mfn;
l4_pgentry_t *l4e;
ASSERT(!pagetable_get_pfn(v->arch.hvm.monitor_table));
/* Guarantee we can get the memory we need */
shadow_prealloc(d, SH_type_monitor_table, CONFIG_PAGING_LEVELS);
m4mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m4mfn)->shadow_flags = 4;
l4e = map_domain_page(m4mfn);
/*
* Create a self-linear mapping, but no shadow-linear mapping. A
* shadow-linear mapping will either be inserted below when creating
* lower level monitor tables, or later in sh_update_cr3().
*/
init_xen_l4_slots(l4e, m4mfn, d, INVALID_MFN, false);
if ( shadow_levels < 4 )
{
mfn_t m3mfn, m2mfn;
l3_pgentry_t *l3e;
/*
* Install an l3 table and an l2 table that will hold the shadow
* linear map entries. This overrides the empty entry that was
* installed by init_xen_l4_slots().
*/
m3mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m3mfn)->shadow_flags = 3;
l4e[l4_table_offset(SH_LINEAR_PT_VIRT_START)]
= l4e_from_mfn(m3mfn, __PAGE_HYPERVISOR_RW);
m2mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m2mfn)->shadow_flags = 2;
l3e = map_domain_page(m3mfn);
l3e[0] = l3e_from_mfn(m2mfn, __PAGE_HYPERVISOR_RW);
unmap_domain_page(l3e);
}
unmap_domain_page(l4e);
return m4mfn;
}
void sh_destroy_monitor_table(const struct vcpu *v, mfn_t mmfn,
unsigned int shadow_levels)
{
struct domain *d = v->domain;
ASSERT(mfn_to_page(mmfn)->u.sh.type == SH_type_monitor_table);
if ( shadow_levels < 4 )
{
mfn_t m3mfn;
l4_pgentry_t *l4e = map_domain_page(mmfn);
l3_pgentry_t *l3e;
unsigned int linear_slot = l4_table_offset(SH_LINEAR_PT_VIRT_START);
/*
* Need to destroy the l3 and l2 monitor pages used
* for the linear map.
*/
ASSERT(l4e_get_flags(l4e[linear_slot]) & _PAGE_PRESENT);
m3mfn = l4e_get_mfn(l4e[linear_slot]);
l3e = map_domain_page(m3mfn);
ASSERT(l3e_get_flags(l3e[0]) & _PAGE_PRESENT);
shadow_free(d, l3e_get_mfn(l3e[0]));
unmap_domain_page(l3e);
shadow_free(d, m3mfn);
unmap_domain_page(l4e);
}
/* Put the memory back in the pool */
shadow_free(d, mmfn);
}
/**************************************************************************/
/* VRAM dirty tracking support */
int shadow_track_dirty_vram(struct domain *d,
xen/arch/x86/mm/shadow/multi.c
-124
View File
@@ -1405,84 +1405,6 @@ make_fl1_shadow(struct domain *d, gfn_t gfn)
}
#if SHADOW_PAGING_LEVELS == GUEST_PAGING_LEVELS && defined(CONFIG_HVM)
mfn_t
sh_make_monitor_table(struct vcpu *v)
{
struct domain *d = v->domain;
ASSERT(pagetable_get_pfn(v->arch.hvm.monitor_table) == 0);
/* Guarantee we can get the memory we need */
shadow_prealloc(d, SH_type_monitor_table, CONFIG_PAGING_LEVELS);
{
mfn_t m4mfn;
l4_pgentry_t *l4e;
m4mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m4mfn)->shadow_flags = 4;
l4e = map_domain_page(m4mfn);
/*
* Create a self-linear mapping, but no shadow-linear mapping. A
* shadow-linear mapping will either be inserted below when creating
* lower level monitor tables, or later in sh_update_cr3().
*/
init_xen_l4_slots(l4e, m4mfn, d, INVALID_MFN, false);
#if SHADOW_PAGING_LEVELS < 4
{
mfn_t m3mfn, m2mfn;
l3_pgentry_t *l3e;
/* Install an l3 table and an l2 table that will hold the shadow
* linear map entries. This overrides the linear map entry that
* was installed by sh_install_xen_entries_in_l4. */
m3mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m3mfn)->shadow_flags = 3;
l4e[shadow_l4_table_offset(SH_LINEAR_PT_VIRT_START)]
= l4e_from_mfn(m3mfn, __PAGE_HYPERVISOR_RW);
m2mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m2mfn)->shadow_flags = 2;
l3e = map_domain_page(m3mfn);
l3e[0] = l3e_from_mfn(m2mfn, __PAGE_HYPERVISOR_RW);
unmap_domain_page(l3e);
if ( is_pv_32bit_domain(d) )
{
l2_pgentry_t *l2t;
/* For 32-bit PV guests, we need to map the 32-bit Xen
* area into its usual VAs in the monitor tables */
m3mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m3mfn)->shadow_flags = 3;
l4e[0] = l4e_from_mfn(m3mfn, __PAGE_HYPERVISOR_RW);
m2mfn = shadow_alloc(d, SH_type_monitor_table, 0);
mfn_to_page(m2mfn)->shadow_flags = 2;
l3e = map_domain_page(m3mfn);
l3e[3] = l3e_from_mfn(m2mfn, _PAGE_PRESENT);
l2t = map_domain_page(m2mfn);
init_xen_pae_l2_slots(l2t, d);
unmap_domain_page(l2t);
unmap_domain_page(l3e);
}
}
#endif /* SHADOW_PAGING_LEVELS < 4 */
unmap_domain_page(l4e);
return m4mfn;
}
}
#endif /* SHADOW_PAGING_LEVELS == GUEST_PAGING_LEVELS */
/**************************************************************************/
/* These functions also take a virtual address and return the level-N
* shadow table mfn and entry, but they create the shadow pagetables if
@@ -1860,50 +1782,6 @@ void sh_destroy_l1_shadow(struct domain *d, mfn_t smfn)
shadow_free(d, smfn);
}
#if SHADOW_PAGING_LEVELS == GUEST_PAGING_LEVELS && defined(CONFIG_HVM)
void sh_destroy_monitor_table(struct vcpu *v, mfn_t mmfn)
{
struct domain *d = v->domain;
ASSERT(mfn_to_page(mmfn)->u.sh.type == SH_type_monitor_table);
#if SHADOW_PAGING_LEVELS != 4
{
mfn_t m3mfn;
l4_pgentry_t *l4e = map_domain_page(mmfn);
l3_pgentry_t *l3e;
int linear_slot = shadow_l4_table_offset(SH_LINEAR_PT_VIRT_START);
/* Need to destroy the l3 and l2 monitor pages used
* for the linear map */
ASSERT(l4e_get_flags(l4e[linear_slot]) & _PAGE_PRESENT);
m3mfn = l4e_get_mfn(l4e[linear_slot]);
l3e = map_domain_page(m3mfn);
ASSERT(l3e_get_flags(l3e[0]) & _PAGE_PRESENT);
shadow_free(d, l3e_get_mfn(l3e[0]));
unmap_domain_page(l3e);
shadow_free(d, m3mfn);
if ( is_pv_32bit_domain(d) )
{
/* Need to destroy the l3 and l2 monitor pages that map the
* Xen VAs at 3GB-4GB */
ASSERT(l4e_get_flags(l4e[0]) & _PAGE_PRESENT);
m3mfn = l4e_get_mfn(l4e[0]);
l3e = map_domain_page(m3mfn);
ASSERT(l3e_get_flags(l3e[3]) & _PAGE_PRESENT);
shadow_free(d, l3e_get_mfn(l3e[3]));
unmap_domain_page(l3e);
shadow_free(d, m3mfn);
}
unmap_domain_page(l4e);
}
#endif
/* Put the memory back in the pool */
shadow_free(d, mmfn);
}
#endif
/**************************************************************************/
/* Functions to destroy non-Xen mappings in a pagetable hierarchy.
* These are called from common code when we are running out of shadow
@@ -4705,8 +4583,6 @@ const struct paging_mode sh_paging_mode = {
.shadow.cmpxchg_guest_entry = sh_cmpxchg_guest_entry,
#endif
#ifdef CONFIG_HVM
.shadow.make_monitor_table = sh_make_monitor_table,
.shadow.destroy_monitor_table = sh_destroy_monitor_table,
#if SHADOW_OPTIMIZATIONS & SHOPT_WRITABLE_HEURISTIC
.shadow.guess_wrmap = sh_guess_wrmap,
#endif
xen/arch/x86/mm/shadow/private.h
+8 -3
View File
@@ -366,9 +366,6 @@ void sh_set_toplevel_shadow(struct vcpu *v,
mfn_t gmfn,
uint32_t shadow_type));
/* Install the xen mappings in various flavours of shadow */
void sh_install_xen_entries_in_l4(struct domain *, mfn_t gl4mfn, mfn_t sl4mfn);
/* Update the shadows in response to a pagetable write from Xen */
int sh_validate_guest_entry(struct vcpu *v, mfn_t gmfn, void *entry, u32 size);
@@ -410,6 +407,14 @@ void shadow_update_paging_modes(struct vcpu *v);
* With user_only == 1, unhooks only the user-mode mappings. */
void shadow_unhook_mappings(struct domain *d, mfn_t smfn, int user_only);
/*
* sh_{make,destroy}_monitor_table() depend only on the number of shadow
* levels.
*/
mfn_t sh_make_monitor_table(const struct vcpu *v, unsigned int shadow_levels);
void sh_destroy_monitor_table(const struct vcpu *v, mfn_t mmfn,
unsigned int shadow_levels);
/* VRAM dirty tracking helpers. */
void shadow_vram_get_mfn(mfn_t mfn, unsigned int l1f,
mfn_t sl1mfn, const void *sl1e,
xen/arch/x86/mm/shadow/types.h
-9
View File
@@ -262,15 +262,6 @@ static inline shadow_l4e_t shadow_l4e_from_mfn(mfn_t mfn, u32 flags)
#define sh_rm_write_access_from_sl1p INTERNAL_NAME(sh_rm_write_access_from_sl1p)
#endif
/* sh_make_monitor_table depends only on the number of shadow levels */
#define sh_make_monitor_table \
SHADOW_SH_NAME(sh_make_monitor_table, SHADOW_PAGING_LEVELS)
#define sh_destroy_monitor_table \
SHADOW_SH_NAME(sh_destroy_monitor_table, SHADOW_PAGING_LEVELS)
mfn_t sh_make_monitor_table(struct vcpu *v);
void sh_destroy_monitor_table(struct vcpu *v, mfn_t mmfn);
#if SHADOW_PAGING_LEVELS == 3
#define MFN_FITS_IN_HVM_CR3(_MFN) !(mfn_x(_MFN) >> 20)
#endif
xen/include/asm-x86/paging.h
-2
View File
@@ -107,8 +107,6 @@ struct shadow_paging_mode {
mfn_t gmfn);
#endif
#ifdef CONFIG_HVM
mfn_t (*make_monitor_table )(struct vcpu *v);
void (*destroy_monitor_table )(struct vcpu *v, mfn_t mmfn);
int (*guess_wrmap )(struct vcpu *v,
unsigned long vaddr, mfn_t gmfn);
void (*pagetable_dying )(paddr_t gpa);
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