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x86/shadow: have just a single instance of sh_set_toplevel_shadow()

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The only guest/shadow level dependent piece here is the call to
sh_make_shadow(). Make a pointer to the respective function an
argument of sh_set_toplevel_shadow(), allowing it to be moved to
common.c.

This implies making get_shadow_status() available to common.c; its set
and delete counterparts are moved along with it.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
This commit is contained in:
Jan Beulich committed 2020-07-21 13:58:56 +02:00
1 parent ef3b0d8d2c
commit 5fd152ea7d
3 files changed
+143 -122
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xen/arch/x86/mm/shadow/common.c
+74
View File
@@ -2560,6 +2560,80 @@ void shadow_update_paging_modes(struct vcpu *v)
paging_unlock(v->domain);
}
/* Set up the top-level shadow and install it in slot 'slot' of shadow_table */
void sh_set_toplevel_shadow(struct vcpu *v,
unsigned int slot,
mfn_t gmfn,
unsigned int root_type,
mfn_t (*make_shadow)(struct vcpu *v,
mfn_t gmfn,
uint32_t shadow_type))
{
mfn_t smfn;
pagetable_t old_entry, new_entry;
struct domain *d = v->domain;
/* Remember the old contents of this slot */
old_entry = v->arch.paging.shadow.shadow_table[slot];
/* Now figure out the new contents: is this a valid guest MFN? */
if ( !mfn_valid(gmfn) )
{
new_entry = pagetable_null();
goto install_new_entry;
}
/* Guest mfn is valid: shadow it and install the shadow */
smfn = get_shadow_status(d, gmfn, root_type);
if ( !mfn_valid(smfn) )
{
/* Make sure there's enough free shadow memory. */
shadow_prealloc(d, root_type, 1);
/* Shadow the page. */
smfn = make_shadow(v, gmfn, root_type);
}
ASSERT(mfn_valid(smfn));
/* Take a ref to this page: it will be released in sh_detach_old_tables()
* or the next call to set_toplevel_shadow() */
if ( sh_get_ref(d, smfn, 0) )
{
/* Pin the shadow and put it (back) on the list of pinned shadows */
sh_pin(d, smfn);
new_entry = pagetable_from_mfn(smfn);
}
else
{
printk(XENLOG_G_ERR "can't install %"PRI_mfn" as toplevel shadow\n",
mfn_x(smfn));
domain_crash(d);
new_entry = pagetable_null();
}
install_new_entry:
/* Done. Install it */
SHADOW_PRINTK("%u [%u] gmfn %#"PRI_mfn" smfn %#"PRI_mfn"\n",
v->arch.paging.mode->shadow.shadow_levels, slot,
mfn_x(gmfn), mfn_x(pagetable_get_mfn(new_entry)));
v->arch.paging.shadow.shadow_table[slot] = new_entry;
/* Decrement the refcount of the old contents of this slot */
if ( !pagetable_is_null(old_entry) )
{
mfn_t old_smfn = pagetable_get_mfn(old_entry);
/* Need to repin the old toplevel shadow if it's been unpinned
* by shadow_prealloc(): in PV mode we're still running on this
* shadow and it's not safe to free it yet. */
if ( !mfn_to_page(old_smfn)->u.sh.pinned && !sh_pin(d, old_smfn) )
{
printk(XENLOG_G_ERR "can't re-pin %"PRI_mfn"\n", mfn_x(old_smfn));
domain_crash(d);
}
sh_put_ref(d, old_smfn, 0);
}
}
/**************************************************************************/
/* Turning on and off shadow features */
xen/arch/x86/mm/shadow/multi.c
+8 -122
View File
@@ -103,7 +103,7 @@ static void sh_flush_local(const struct domain *d)
/**************************************************************************/
/* Hash table mapping from guest pagetables to shadows
*
* Normal case: maps the mfn of a guest page to the mfn of its shadow page.
* normal case: see private.h.
* FL1's: maps the *gfn* of the start of a superpage to the mfn of a
* shadow L1 which maps its "splinters".
*/
@@ -117,16 +117,6 @@ get_fl1_shadow_status(struct domain *d, gfn_t gfn)
return smfn;
}
static inline mfn_t
get_shadow_status(struct domain *d, mfn_t gmfn, u32 shadow_type)
/* Look for shadows in the hash table */
{
mfn_t smfn = shadow_hash_lookup(d, mfn_x(gmfn), shadow_type);
ASSERT(!mfn_valid(smfn) || mfn_to_page(smfn)->u.sh.head);
perfc_incr(shadow_get_shadow_status);
return smfn;
}
static inline void
set_fl1_shadow_status(struct domain *d, gfn_t gfn, mfn_t smfn)
/* Put an FL1 shadow into the hash table */
@@ -138,27 +128,6 @@ set_fl1_shadow_status(struct domain *d, gfn_t gfn, mfn_t smfn)
shadow_hash_insert(d, gfn_x(gfn), SH_type_fl1_shadow, smfn);
}
static inline void
set_shadow_status(struct domain *d, mfn_t gmfn, u32 shadow_type, mfn_t smfn)
/* Put a shadow into the hash table */
{
int res;
SHADOW_PRINTK("d%d gmfn=%lx, type=%08x, smfn=%lx\n",
d->domain_id, mfn_x(gmfn), shadow_type, mfn_x(smfn));
ASSERT(mfn_to_page(smfn)->u.sh.head);
/* 32-bit PV guests don't own their l4 pages so can't get_page them */
if ( !is_pv_32bit_domain(d) || shadow_type != SH_type_l4_64_shadow )
{
res = get_page(mfn_to_page(gmfn), d);
ASSERT(res == 1);
}
shadow_hash_insert(d, mfn_x(gmfn), shadow_type, smfn);
}
static inline void
delete_fl1_shadow_status(struct domain *d, gfn_t gfn, mfn_t smfn)
/* Remove a shadow from the hash table */
@@ -169,19 +138,6 @@ delete_fl1_shadow_status(struct domain *d, gfn_t gfn, mfn_t smfn)
shadow_hash_delete(d, gfn_x(gfn), SH_type_fl1_shadow, smfn);
}
static inline void
delete_shadow_status(struct domain *d, mfn_t gmfn, u32 shadow_type, mfn_t smfn)
/* Remove a shadow from the hash table */
{
SHADOW_PRINTK("d%d gmfn=%"PRI_mfn", type=%08x, smfn=%"PRI_mfn"\n",
d->domain_id, mfn_x(gmfn), shadow_type, mfn_x(smfn));
ASSERT(mfn_to_page(smfn)->u.sh.head);
shadow_hash_delete(d, mfn_x(gmfn), shadow_type, smfn);
/* 32-bit PV guests don't own their l4 pages; see set_shadow_status */
if ( !is_pv_32bit_domain(d) || shadow_type != SH_type_l4_64_shadow )
put_page(mfn_to_page(gmfn));
}
/**************************************************************************/
/* Functions for walking the guest page tables */
@@ -3845,78 +3801,6 @@ sh_detach_old_tables(struct vcpu *v)
}
}
/* Set up the top-level shadow and install it in slot 'slot' of shadow_table */
static void
sh_set_toplevel_shadow(struct vcpu *v,
unsigned int slot,
mfn_t gmfn,
unsigned int root_type)
{
mfn_t smfn;
pagetable_t old_entry, new_entry;
struct domain *d = v->domain;
/* Remember the old contents of this slot */
old_entry = v->arch.paging.shadow.shadow_table[slot];
/* Now figure out the new contents: is this a valid guest MFN? */
if ( !mfn_valid(gmfn) )
{
new_entry = pagetable_null();
goto install_new_entry;
}
/* Guest mfn is valid: shadow it and install the shadow */
smfn = get_shadow_status(d, gmfn, root_type);
if ( !mfn_valid(smfn) )
{
/* Make sure there's enough free shadow memory. */
shadow_prealloc(d, root_type, 1);
/* Shadow the page. */
smfn = sh_make_shadow(v, gmfn, root_type);
}
ASSERT(mfn_valid(smfn));
/* Take a ref to this page: it will be released in sh_detach_old_tables()
* or the next call to set_toplevel_shadow() */
if ( sh_get_ref(d, smfn, 0) )
{
/* Pin the shadow and put it (back) on the list of pinned shadows */
sh_pin(d, smfn);
new_entry = pagetable_from_mfn(smfn);
}
else
{
printk(XENLOG_G_ERR "can't install %"PRI_mfn" as toplevel shadow\n",
mfn_x(smfn));
domain_crash(d);
new_entry = pagetable_null();
}
install_new_entry:
/* Done. Install it */
SHADOW_PRINTK("%u/%u [%u] gmfn %#"PRI_mfn" smfn %#"PRI_mfn"\n",
GUEST_PAGING_LEVELS, SHADOW_PAGING_LEVELS, slot,
mfn_x(gmfn), mfn_x(pagetable_get_mfn(new_entry)));
v->arch.paging.shadow.shadow_table[slot] = new_entry;
/* Decrement the refcount of the old contents of this slot */
if ( !pagetable_is_null(old_entry) ) {
mfn_t old_smfn = pagetable_get_mfn(old_entry);
/* Need to repin the old toplevel shadow if it's been unpinned
* by shadow_prealloc(): in PV mode we're still running on this
* shadow and it's not safe to free it yet. */
if ( !mfn_to_page(old_smfn)->u.sh.pinned && !sh_pin(d, old_smfn) )
{
printk(XENLOG_G_ERR "can't re-pin %"PRI_mfn"\n", mfn_x(old_smfn));
domain_crash(d);
}
sh_put_ref(d, old_smfn, 0);
}
}
static void
sh_update_cr3(struct vcpu *v, int do_locking, bool noflush)
/* Updates vcpu->arch.cr3 after the guest has changed CR3.
@@ -4014,7 +3898,7 @@ sh_update_cr3(struct vcpu *v, int do_locking, bool noflush)
#if GUEST_PAGING_LEVELS == 2
if ( sh_remove_write_access(d, gmfn, 2, 0) != 0 )
guest_flush_tlb_mask(d, d->dirty_cpumask);
sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l2_shadow);
sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l2_shadow, sh_make_shadow);
#elif GUEST_PAGING_LEVELS == 3
/* PAE guests have four shadow_table entries, based on the
* current values of the guest's four l3es. */
@@ -4048,18 +3932,20 @@ sh_update_cr3(struct vcpu *v, int do_locking, bool noflush)
if ( p2m_is_ram(p2mt) )
sh_set_toplevel_shadow(v, i, gl2mfn, (i == 3)
? SH_type_l2h_shadow
: SH_type_l2_shadow);
: SH_type_l2_shadow,
sh_make_shadow);
else
sh_set_toplevel_shadow(v, i, INVALID_MFN, 0);
sh_set_toplevel_shadow(v, i, INVALID_MFN, 0,
sh_make_shadow);
}
else
sh_set_toplevel_shadow(v, i, INVALID_MFN, 0);
sh_set_toplevel_shadow(v, i, INVALID_MFN, 0, sh_make_shadow);
}
}
#elif GUEST_PAGING_LEVELS == 4
if ( sh_remove_write_access(d, gmfn, 4, 0) != 0 )
guest_flush_tlb_mask(d, d->dirty_cpumask);
sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l4_shadow);
sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l4_shadow, sh_make_shadow);
if ( !shadow_mode_external(d) && !is_pv_32bit_domain(d) )
{
mfn_t smfn = pagetable_get_mfn(v->arch.paging.shadow.shadow_table[0]);
xen/arch/x86/mm/shadow/private.h
+61
View File
@@ -357,6 +357,15 @@ mfn_t shadow_alloc(struct domain *d,
unsigned long backpointer);
void shadow_free(struct domain *d, mfn_t smfn);
/* Set up the top-level shadow and install it in slot 'slot' of shadow_table */
void sh_set_toplevel_shadow(struct vcpu *v,
unsigned int slot,
mfn_t gmfn,
unsigned int root_type,
mfn_t (*make_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);
@@ -701,6 +710,58 @@ static inline void sh_unpin(struct domain *d, mfn_t smfn)
}
/**************************************************************************/
/* Hash table mapping from guest pagetables to shadows
*
* Normal case: maps the mfn of a guest page to the mfn of its shadow page.
* FL1's: see multi.c.
*/
static inline mfn_t
get_shadow_status(struct domain *d, mfn_t gmfn, u32 shadow_type)
/* Look for shadows in the hash table */
{
mfn_t smfn = shadow_hash_lookup(d, mfn_x(gmfn), shadow_type);
ASSERT(!mfn_valid(smfn) || mfn_to_page(smfn)->u.sh.head);
perfc_incr(shadow_get_shadow_status);
return smfn;
}
static inline void
set_shadow_status(struct domain *d, mfn_t gmfn, u32 shadow_type, mfn_t smfn)
/* Put a shadow into the hash table */
{
int res;
SHADOW_PRINTK("d%d gmfn=%lx, type=%08x, smfn=%lx\n",
d->domain_id, mfn_x(gmfn), shadow_type, mfn_x(smfn));
ASSERT(mfn_to_page(smfn)->u.sh.head);
/* 32-bit PV guests don't own their l4 pages so can't get_page them */
if ( !is_pv_32bit_domain(d) || shadow_type != SH_type_l4_64_shadow )
{
res = get_page(mfn_to_page(gmfn), d);
ASSERT(res == 1);
}
shadow_hash_insert(d, mfn_x(gmfn), shadow_type, smfn);
}
static inline void
delete_shadow_status(struct domain *d, mfn_t gmfn, u32 shadow_type, mfn_t smfn)
/* Remove a shadow from the hash table */
{
SHADOW_PRINTK("d%d gmfn=%"PRI_mfn", type=%08x, smfn=%"PRI_mfn"\n",
d->domain_id, mfn_x(gmfn), shadow_type, mfn_x(smfn));
ASSERT(mfn_to_page(smfn)->u.sh.head);
shadow_hash_delete(d, mfn_x(gmfn), shadow_type, smfn);
/* 32-bit PV guests don't own their l4 pages; see set_shadow_status */
if ( !is_pv_32bit_domain(d) || shadow_type != SH_type_l4_64_shadow )
put_page(mfn_to_page(gmfn));
}
/**************************************************************************/
/* PTE-write emulation. */
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