|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/EPT: split super pages upon mismatching memory types
commit 3d90d6e69fe219ce77a3e85b8637cfd62d3a4e0a
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Apr 10 16:05:12 2014 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Apr 10 16:05:12 2014 +0200
x86/EPT: split super pages upon mismatching memory types
... between constituent pages. To indicate such, the page order is
being passed down to the vMTRR routines, with a negative return value
(possible only on order-non-zero pages) indicating such collisions.
Some code redundancy reduction is being done to ept_set_entry() along
the way, allowing the new handling to be centralized to a single place
there.
In order to keep ept_set_entry() fast and simple, the actual splitting
is being deferred to the EPT_MISCONFIG VM exit handler.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Tim Deegan <tim@xxxxxxx>
Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
xen/arch/x86/hvm/mtrr.c | 76 ++++++++++++++++++++++++++-----------------
xen/arch/x86/mm/p2m-ept.c | 64 ++++++++++++++++++------------------
xen/include/asm-x86/mtrr.h | 5 ++-
3 files changed, 81 insertions(+), 64 deletions(-)
diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c
index ae24efa..dde70a6 100644
--- a/xen/arch/x86/hvm/mtrr.c
+++ b/xen/arch/x86/hvm/mtrr.c
@@ -222,30 +222,40 @@ void hvm_vcpu_cacheattr_destroy(struct vcpu *v)
/*
* Get MTRR memory type for physical address pa.
+ *
+ * May return a negative value when order > 0, indicating to the caller
+ * that the respective mapping needs splitting.
*/
-static uint8_t get_mtrr_type(struct mtrr_state *m, paddr_t pa)
+static int get_mtrr_type(const struct mtrr_state *m,
+ paddr_t pa, unsigned int order)
{
- int32_t addr, seg, index;
uint8_t overlap_mtrr = 0;
uint8_t overlap_mtrr_pos = 0;
- uint64_t phys_base;
- uint64_t phys_mask;
- uint8_t num_var_ranges = m->mtrr_cap & 0xff;
+ uint64_t mask = -(uint64_t)PAGE_SIZE << order;
+ unsigned int seg, num_var_ranges = m->mtrr_cap & 0xff;
if ( unlikely(!(m->enabled & 0x2)) )
return MTRR_TYPE_UNCACHABLE;
+ pa &= mask;
if ( (pa < 0x100000) && (m->enabled & 1) )
{
- /* Fixed range MTRR takes effective */
- addr = (uint32_t) pa;
+ /* Fixed range MTRR takes effect. */
+ uint32_t addr = (uint32_t)pa, index;
+
if ( addr < 0x80000 )
{
+ /* 0x00000 ... 0x7FFFF in 64k steps */
+ if ( order > 4 )
+ return -1;
seg = (addr >> 16);
return m->fixed_ranges[seg];
}
else if ( addr < 0xc0000 )
{
+ /* 0x80000 ... 0xBFFFF in 16k steps */
+ if ( order > 2 )
+ return -1;
seg = (addr - 0x80000) >> 14;
index = (seg >> 3) + 1;
seg &= 7; /* select 0-7 segments */
@@ -253,7 +263,9 @@ static uint8_t get_mtrr_type(struct mtrr_state *m, paddr_t
pa)
}
else
{
- /* 0xC0000 --- 0x100000 */
+ /* 0xC0000 ... 0xFFFFF in 4k steps */
+ if ( order )
+ return -1;
seg = (addr - 0xc0000) >> 12;
index = (seg >> 3) + 3;
seg &= 7; /* select 0-7 segments */
@@ -264,14 +276,15 @@ static uint8_t get_mtrr_type(struct mtrr_state *m,
paddr_t pa)
/* Match with variable MTRRs. */
for ( seg = 0; seg < num_var_ranges; seg++ )
{
- phys_base = ((uint64_t*)m->var_ranges)[seg*2];
- phys_mask = ((uint64_t*)m->var_ranges)[seg*2 + 1];
+ uint64_t phys_base = m->var_ranges[seg].base;
+ uint64_t phys_mask = m->var_ranges[seg].mask;
+
if ( phys_mask & MTRR_PHYSMASK_VALID )
{
- if ( ((uint64_t) pa & phys_mask) >> MTRR_PHYSMASK_SHIFT ==
- (phys_base & phys_mask) >> MTRR_PHYSMASK_SHIFT )
+ phys_mask &= mask;
+ if ( (pa & phys_mask) == (phys_base & phys_mask) )
{
- if ( unlikely(m->overlapped) )
+ if ( unlikely(m->overlapped) || order )
{
overlap_mtrr |= 1 << (phys_base & MTRR_PHYSBASE_TYPE_MASK);
overlap_mtrr_pos = phys_base & MTRR_PHYSBASE_TYPE_MASK;
@@ -285,23 +298,24 @@ static uint8_t get_mtrr_type(struct mtrr_state *m,
paddr_t pa)
}
}
- /* Overlapped or not found. */
+ /* Not found? */
if ( unlikely(overlap_mtrr == 0) )
return m->def_type;
- if ( likely(!(overlap_mtrr & ~( ((uint8_t)1) << overlap_mtrr_pos ))) )
- /* Covers both one variable memory range matches and
- * two or more identical match.
- */
+ /* One match, or multiple identical ones? */
+ if ( likely(overlap_mtrr == (1 << overlap_mtrr_pos)) )
return overlap_mtrr_pos;
+ if ( order )
+ return -1;
+
+ /* Two or more matches, one being UC? */
if ( overlap_mtrr & (1 << MTRR_TYPE_UNCACHABLE) )
- /* Two or more match, one is UC. */
return MTRR_TYPE_UNCACHABLE;
- if ( !(overlap_mtrr &
- ~((1 << MTRR_TYPE_WRTHROUGH) | (1 << MTRR_TYPE_WRBACK))) )
- /* Two or more match, WT and WB. */
+ /* Two or more matches, all of them WT and WB? */
+ if ( overlap_mtrr ==
+ ((1 << MTRR_TYPE_WRTHROUGH) | (1 << MTRR_TYPE_WRBACK)) )
return MTRR_TYPE_WRTHROUGH;
/* Behaviour is undefined, but return the last overlapped type. */
@@ -341,7 +355,7 @@ static uint8_t effective_mm_type(struct mtrr_state *m,
* just use it
*/
if ( gmtrr_mtype == NO_HARDCODE_MEM_TYPE )
- mtrr_mtype = get_mtrr_type(m, gpa);
+ mtrr_mtype = get_mtrr_type(m, gpa, 0);
else
mtrr_mtype = gmtrr_mtype;
@@ -370,7 +384,7 @@ uint32_t get_pat_flags(struct vcpu *v,
guest_eff_mm_type = effective_mm_type(g, pat, gpaddr,
gl1e_flags, gmtrr_mtype);
/* 2. Get the memory type of host physical address, with MTRR */
- shadow_mtrr_type = get_mtrr_type(&mtrr_state, spaddr);
+ shadow_mtrr_type = get_mtrr_type(&mtrr_state, spaddr, 0);
/* 3. Find the memory type in PAT, with host MTRR memory type
* and guest effective memory type.
@@ -703,10 +717,10 @@ void memory_type_changed(struct domain *d)
p2m_memory_type_changed(d);
}
-uint8_t epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn,
- uint8_t *ipat, bool_t direct_mmio)
+int epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn,
+ unsigned int order, uint8_t *ipat, bool_t direct_mmio)
{
- uint8_t gmtrr_mtype, hmtrr_mtype;
+ int gmtrr_mtype, hmtrr_mtype;
uint32_t type;
struct vcpu *v = current;
@@ -747,10 +761,12 @@ uint8_t epte_get_entry_emt(struct domain *d, unsigned
long gfn, mfn_t mfn,
}
gmtrr_mtype = is_hvm_domain(d) && v ?
- get_mtrr_type(&v->arch.hvm_vcpu.mtrr, (gfn << PAGE_SHIFT)) :
+ get_mtrr_type(&v->arch.hvm_vcpu.mtrr,
+ gfn << PAGE_SHIFT, order) :
MTRR_TYPE_WRBACK;
-
- hmtrr_mtype = get_mtrr_type(&mtrr_state, (mfn_x(mfn) << PAGE_SHIFT));
+ hmtrr_mtype = get_mtrr_type(&mtrr_state, mfn_x(mfn) << PAGE_SHIFT, order);
+ if ( gmtrr_mtype < 0 || hmtrr_mtype < 0 )
+ return -1;
/* If both types match we're fine. */
if ( likely(gmtrr_mtype == hmtrr_mtype) )
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 342fc70..3f84915 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -337,7 +337,7 @@ bool_t ept_handle_misconfig(uint64_t gpa)
if ( !is_epte_valid(&e) || !is_epte_present(&e) )
continue;
e.emt = epte_get_entry_emt(p2m->domain, gfn + i,
- _mfn(e.mfn), &ipat,
+ _mfn(e.mfn), 0, &ipat,
e.sa_p2mt == p2m_mmio_direct);
e.ipat = ipat;
atomic_write_ept_entry(&epte[i], e);
@@ -345,9 +345,22 @@ bool_t ept_handle_misconfig(uint64_t gpa)
}
else
{
- e.emt = epte_get_entry_emt(p2m->domain, gfn, _mfn(e.mfn),
- &ipat,
- e.sa_p2mt == p2m_mmio_direct);
+ int emt = epte_get_entry_emt(p2m->domain, gfn, _mfn(e.mfn),
+ level * EPT_TABLE_ORDER, &ipat,
+ e.sa_p2mt == p2m_mmio_direct);
+ if ( unlikely(emt < 0) )
+ {
+ unmap_domain_page(epte);
+ if ( ept_split_super_page(p2m, &e, level, level - 1) )
+ {
+ mfn = e.mfn;
+ continue;
+ }
+ ept_free_entry(p2m, &e, level);
+ okay = 0;
+ break;
+ }
+ e.emt = emt;
e.ipat = ipat;
atomic_write_ept_entry(&epte[i], e);
}
@@ -408,6 +421,7 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn,
mfn_t mfn,
int vtd_pte_present = 0;
int needs_sync = 1;
ept_entry_t old_entry = { .epte = 0 };
+ ept_entry_t new_entry = { .epte = 0 };
struct ept_data *ept = &p2m->ept;
struct domain *d = p2m->domain;
@@ -457,7 +471,6 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn,
mfn_t mfn,
if ( i == target )
{
/* We reached the target level. */
- ept_entry_t new_entry = { .epte = 0 };
/* No need to flush if the old entry wasn't valid */
if ( !is_epte_present(ept_entry) )
@@ -468,35 +481,11 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn,
mfn_t mfn,
*
* Read-then-write is OK because we hold the p2m lock. */
old_entry = *ept_entry;
-
- if ( mfn_valid(mfn_x(mfn)) || direct_mmio || p2m_is_paged(p2mt) ||
- (p2mt == p2m_ram_paging_in) )
- {
- /* Construct the new entry, and then write it once */
- new_entry.emt = epte_get_entry_emt(p2m->domain, gfn, mfn, &ipat,
- direct_mmio);
-
- new_entry.ipat = ipat;
- new_entry.sp = !!order;
- new_entry.sa_p2mt = p2mt;
- new_entry.access = p2ma;
- new_entry.snp = (iommu_enabled && iommu_snoop);
-
- new_entry.mfn = mfn_x(mfn);
-
- if ( old_entry.mfn == new_entry.mfn )
- need_modify_vtd_table = 0;
-
- ept_p2m_type_to_flags(&new_entry, p2mt, p2ma);
- }
-
- atomic_write_ept_entry(ept_entry, new_entry);
}
else
{
/* We need to split the original page. */
ept_entry_t split_ept_entry;
- ept_entry_t new_entry = { .epte = 0 };
ASSERT(is_epte_superpage(ept_entry));
@@ -520,8 +509,19 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn,
mfn_t mfn,
ASSERT(i == target);
ept_entry = table + (gfn_remainder >> (i * EPT_TABLE_ORDER));
+ }
+
+ if ( mfn_valid(mfn_x(mfn)) || direct_mmio || p2m_is_paged(p2mt) ||
+ (p2mt == p2m_ram_paging_in) )
+ {
+ int emt = epte_get_entry_emt(p2m->domain, gfn, mfn,
+ i * EPT_TABLE_ORDER, &ipat, direct_mmio);
+
+ if ( emt >= 0 )
+ new_entry.emt = emt;
+ else /* ept_handle_misconfig() will need to take care of this. */
+ new_entry.emt = MTRR_NUM_TYPES;
- new_entry.emt = epte_get_entry_emt(d, gfn, mfn, &ipat, direct_mmio);
new_entry.ipat = ipat;
new_entry.sp = !!i;
new_entry.sa_p2mt = p2mt;
@@ -536,10 +536,10 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn,
mfn_t mfn,
need_modify_vtd_table = 0;
ept_p2m_type_to_flags(&new_entry, p2mt, p2ma);
-
- atomic_write_ept_entry(ept_entry, new_entry);
}
+ atomic_write_ept_entry(ept_entry, new_entry);
+
/* Track the highest gfn for which we have ever had a valid mapping */
if ( p2mt != p2m_invalid &&
(gfn + (1UL << order) - 1 > p2m->max_mapped_pfn) )
diff --git a/xen/include/asm-x86/mtrr.h b/xen/include/asm-x86/mtrr.h
index b3f238c..328ba04 100644
--- a/xen/include/asm-x86/mtrr.h
+++ b/xen/include/asm-x86/mtrr.h
@@ -72,8 +72,9 @@ extern int mtrr_del_page(int reg, unsigned long base,
unsigned long size);
extern void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi);
extern u32 get_pat_flags(struct vcpu *v, u32 gl1e_flags, paddr_t gpaddr,
paddr_t spaddr, uint8_t gmtrr_mtype);
-extern uint8_t epte_get_entry_emt(struct domain *d, unsigned long gfn,
- mfn_t mfn, uint8_t *ipat, bool_t
direct_mmio);
+extern int epte_get_entry_emt(struct domain *, unsigned long gfn, mfn_t mfn,
+ unsigned int order, uint8_t *ipat,
+ bool_t direct_mmio);
extern void ept_change_entry_emt_with_range(
struct domain *d, unsigned long start_gfn, unsigned long end_gfn);
extern unsigned char pat_type_2_pte_flags(unsigned char pat_type);
--
generated by git-patchbot for /home/xen/git/xen.git#master
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |