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-rw-r--r--xen/arch/x86/hvm/emulate.c14
-rw-r--r--xen/arch/x86/hvm/hvm.c23
-rw-r--r--xen/arch/x86/hvm/intercept.c19
-rw-r--r--xen/arch/x86/hvm/io.c16
-rw-r--r--xen/arch/x86/mm/guest_walk.c92
-rw-r--r--xen/arch/x86/mm/hap/guest_walk.c18
-rw-r--r--xen/include/asm-x86/hvm/support.h1
-rw-r--r--xen/include/asm-x86/page.h1
-rw-r--r--xen/include/asm-x86/processor.h1
9 files changed, 124 insertions, 61 deletions
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index a636c9bef6..88b1eb1946 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -62,12 +62,14 @@ static int hvmemul_do_io(
int rc;
/* Check for paged out page */
- ram_mfn = gfn_to_mfn(current->domain, ram_gfn, &p2mt);
+ ram_mfn = gfn_to_mfn_unshare(current->domain, ram_gfn, &p2mt, 0);
if ( p2m_is_paging(p2mt) )
{
p2m_mem_paging_populate(curr->domain, ram_gfn);
return X86EMUL_RETRY;
}
+ if ( p2m_is_shared(p2mt) )
+ return X86EMUL_RETRY;
/*
* Weird-sized accesses have undefined behaviour: we discard writes
@@ -282,7 +284,7 @@ static int hvmemul_linear_to_phys(
}
else if ( (pfn = paging_gva_to_gfn(curr, addr, &pfec)) == INVALID_GFN )
{
- if ( pfec == PFEC_page_paged )
+ if ( pfec == PFEC_page_paged || pfec == PFEC_page_shared )
return X86EMUL_RETRY;
hvm_inject_exception(TRAP_page_fault, pfec, addr);
return X86EMUL_EXCEPTION;
@@ -299,7 +301,7 @@ static int hvmemul_linear_to_phys(
/* Is it contiguous with the preceding PFNs? If not then we're done. */
if ( (npfn == INVALID_GFN) || (npfn != (pfn + (reverse ? -i : i))) )
{
- if ( pfec == PFEC_page_paged )
+ if ( pfec == PFEC_page_paged || pfec == PFEC_page_shared )
return X86EMUL_RETRY;
done /= bytes_per_rep;
if ( done == 0 )
@@ -441,6 +443,8 @@ static int __hvmemul_read(
return hvmemul_do_mmio(gpa, &reps, bytes, 0, IOREQ_READ, 0, p_data);
case HVMCOPY_gfn_paged_out:
return X86EMUL_RETRY;
+ case HVMCOPY_gfn_shared:
+ return X86EMUL_RETRY;
default:
break;
}
@@ -533,6 +537,8 @@ static int hvmemul_write(
IOREQ_WRITE, 0, p_data);
case HVMCOPY_gfn_paged_out:
return X86EMUL_RETRY;
+ case HVMCOPY_gfn_shared:
+ return X86EMUL_RETRY;
default:
break;
}
@@ -708,6 +714,8 @@ static int hvmemul_rep_movs(
if ( rc == HVMCOPY_gfn_paged_out )
return X86EMUL_RETRY;
+ if ( rc == HVMCOPY_gfn_shared )
+ return X86EMUL_RETRY;
if ( rc != HVMCOPY_okay )
{
gdprintk(XENLOG_WARNING, "Failed memory-to-memory REP MOVS: sgpa=%"
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 4fc1b93488..e18e94f349 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -311,7 +311,7 @@ static int hvm_set_ioreq_page(
unsigned long mfn;
void *va;
- mfn = mfn_x(gfn_to_mfn(d, gmfn, &p2mt));
+ mfn = mfn_x(gfn_to_mfn_unshare(d, gmfn, &p2mt, 0));
if ( !p2m_is_ram(p2mt) )
return -EINVAL;
if ( p2m_is_paging(p2mt) )
@@ -319,6 +319,8 @@ static int hvm_set_ioreq_page(
p2m_mem_paging_populate(d, gmfn);
return -ENOENT;
}
+ if ( p2m_is_shared(p2mt) )
+ return -ENOENT;
ASSERT(mfn_valid(mfn));
page = mfn_to_page(mfn);
@@ -1323,7 +1325,7 @@ static void *hvm_map_entry(unsigned long va)
* we still treat it as a kernel-mode read (i.e. no access checks). */
pfec = PFEC_page_present;
gfn = paging_gva_to_gfn(current, va, &pfec);
- if ( pfec == PFEC_page_paged )
+ if ( pfec == PFEC_page_paged || pfec == PFEC_page_shared )
return NULL;
mfn = mfn_x(gfn_to_mfn_unshare(current->domain, gfn, &p2mt, 0));
if ( p2m_is_paging(p2mt) )
@@ -1557,6 +1559,8 @@ void hvm_task_switch(
goto out;
if ( rc == HVMCOPY_gfn_paged_out )
goto out;
+ if ( rc == HVMCOPY_gfn_shared )
+ goto out;
eflags = regs->eflags;
if ( taskswitch_reason == TSW_iret )
@@ -1595,6 +1599,8 @@ void hvm_task_switch(
goto out;
if ( rc == HVMCOPY_gfn_paged_out )
goto out;
+ if ( rc == HVMCOPY_gfn_shared )
+ goto out;
rc = hvm_copy_from_guest_virt(
&tss, tr.base, sizeof(tss), PFEC_page_present);
@@ -1602,6 +1608,11 @@ void hvm_task_switch(
goto out;
if ( rc == HVMCOPY_gfn_paged_out )
goto out;
+ /* Note: this could be optimised, if the callee functions knew we want RO
+ * access */
+ if ( rc == HVMCOPY_gfn_shared )
+ goto out;
+
if ( hvm_set_cr3(tss.cr3) )
goto out;
@@ -1639,6 +1650,8 @@ void hvm_task_switch(
exn_raised = 1;
if ( rc == HVMCOPY_gfn_paged_out )
goto out;
+ if ( rc == HVMCOPY_gfn_shared )
+ goto out;
if ( (tss.trace & 1) && !exn_raised )
hvm_inject_exception(TRAP_debug, tss_sel & 0xfff8, 0);
@@ -1700,6 +1713,8 @@ static enum hvm_copy_result __hvm_copy(
{
if ( pfec == PFEC_page_paged )
return HVMCOPY_gfn_paged_out;
+ if ( pfec == PFEC_page_shared )
+ return HVMCOPY_gfn_shared;
if ( flags & HVMCOPY_fault )
hvm_inject_exception(TRAP_page_fault, pfec, addr);
return HVMCOPY_bad_gva_to_gfn;
@@ -1710,13 +1725,15 @@ static enum hvm_copy_result __hvm_copy(
gfn = addr >> PAGE_SHIFT;
}
- mfn = mfn_x(gfn_to_mfn_current(gfn, &p2mt));
+ mfn = mfn_x(gfn_to_mfn_unshare(current->domain, gfn, &p2mt, 0));
if ( p2m_is_paging(p2mt) )
{
p2m_mem_paging_populate(curr->domain, gfn);
return HVMCOPY_gfn_paged_out;
}
+ if ( p2m_is_shared(p2mt) )
+ return HVMCOPY_gfn_shared;
if ( p2m_is_grant(p2mt) )
return HVMCOPY_unhandleable;
if ( !p2m_is_ram(p2mt) )
diff --git a/xen/arch/x86/hvm/intercept.c b/xen/arch/x86/hvm/intercept.c
index 841dec8921..4af9e3d112 100644
--- a/xen/arch/x86/hvm/intercept.c
+++ b/xen/arch/x86/hvm/intercept.c
@@ -72,12 +72,17 @@ static int hvm_mmio_access(struct vcpu *v,
{
for ( i = 0; i < p->count; i++ )
{
+ int ret;
+
rc = read_handler(v, p->addr + (sign * i * p->size), p->size,
&data);
if ( rc != X86EMUL_OKAY )
break;
- if ( hvm_copy_to_guest_phys(p->data + (sign * i * p->size), &data,
- p->size) == HVMCOPY_gfn_paged_out )
+ ret = hvm_copy_to_guest_phys(p->data + (sign * i * p->size),
+ &data,
+ p->size);
+ if ( (ret == HVMCOPY_gfn_paged_out) ||
+ (ret == HVMCOPY_gfn_shared) )
{
rc = X86EMUL_RETRY;
break;
@@ -88,9 +93,13 @@ static int hvm_mmio_access(struct vcpu *v,
{
for ( i = 0; i < p->count; i++ )
{
- if ( hvm_copy_from_guest_phys(&data,
- p->data + (sign * i * p->size),
- p->size) == HVMCOPY_gfn_paged_out )
+ int ret;
+
+ ret = hvm_copy_from_guest_phys(&data,
+ p->data + (sign * i * p->size),
+ p->size);
+ if ( (ret == HVMCOPY_gfn_paged_out) ||
+ (ret == HVMCOPY_gfn_shared) )
{
rc = X86EMUL_RETRY;
break;
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 29079f296d..3c31a6d2e4 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -263,8 +263,11 @@ static int dpci_ioport_read(uint32_t mport, ioreq_t *p)
if ( p->data_is_ptr )
{
- if ( hvm_copy_to_guest_phys(p->data + (sign * i * p->size), &data,
- p->size) == HVMCOPY_gfn_paged_out )
+ int ret;
+ ret = hvm_copy_to_guest_phys(p->data + (sign * i * p->size), &data,
+ p->size);
+ if ( (ret == HVMCOPY_gfn_paged_out) ||
+ (ret == HVMCOPY_gfn_shared) )
return X86EMUL_RETRY;
}
else
@@ -284,8 +287,13 @@ static int dpci_ioport_write(uint32_t mport, ioreq_t *p)
data = p->data;
if ( p->data_is_ptr )
{
- if ( hvm_copy_from_guest_phys(&data, p->data + (sign * i * p->size),
- p->size) == HVMCOPY_gfn_paged_out )
+ int ret;
+
+ ret = hvm_copy_from_guest_phys(&data,
+ p->data + (sign * i * p->size),
+ p->size);
+ if ( (ret == HVMCOPY_gfn_paged_out) &&
+ (ret == HVMCOPY_gfn_shared) )
return X86EMUL_RETRY;
}
diff --git a/xen/arch/x86/mm/guest_walk.c b/xen/arch/x86/mm/guest_walk.c
index b0f42f328a..5a4f491e2b 100644
--- a/xen/arch/x86/mm/guest_walk.c
+++ b/xen/arch/x86/mm/guest_walk.c
@@ -86,6 +86,36 @@ static uint32_t set_ad_bits(void *guest_p, void *walk_p, int set_dirty)
return 0;
}
+static inline void *map_domain_gfn(struct domain *d,
+ gfn_t gfn,
+ mfn_t *mfn,
+ p2m_type_t *p2mt,
+ uint32_t *rc)
+{
+ /* Translate the gfn, unsharing if shared */
+ *mfn = gfn_to_mfn_unshare(d, gfn_x(gfn), p2mt, 0);
+ if ( p2m_is_paging(*p2mt) )
+ {
+ p2m_mem_paging_populate(d, gfn_x(gfn));
+
+ *rc = _PAGE_PAGED;
+ return NULL;
+ }
+ if ( p2m_is_shared(*p2mt) )
+ {
+ *rc = _PAGE_SHARED;
+ return NULL;
+ }
+ if ( !p2m_is_ram(*p2mt) )
+ {
+ *rc |= _PAGE_PRESENT;
+ return NULL;
+ }
+ ASSERT(mfn_valid(mfn_x(*mfn)));
+
+ return map_domain_page(mfn_x(*mfn));
+}
+
/* Walk the guest pagetables, after the manner of a hardware walker. */
uint32_t
@@ -124,23 +154,14 @@ guest_walk_tables(struct vcpu *v, unsigned long va, walk_t *gw,
if ( rc & _PAGE_PRESENT ) goto out;
/* Map the l3 table */
- gw->l3mfn = gfn_to_mfn(d, guest_l4e_get_gfn(gw->l4e), &p2mt);
- if ( p2m_is_paging(p2mt) )
- {
- p2m_mem_paging_populate(d, gfn_x(guest_l4e_get_gfn(gw->l4e)));
-
- rc = _PAGE_PAGED;
- goto out;
- }
- if ( !p2m_is_ram(p2mt) )
- {
- rc |= _PAGE_PRESENT;
+ l3p = map_domain_gfn(d,
+ guest_l4e_get_gfn(gw->l4e),
+ &gw->l3mfn,
+ &p2mt,
+ &rc);
+ if(l3p == NULL)
goto out;
- }
- ASSERT(mfn_valid(mfn_x(gw->l3mfn)));
-
/* Get the l3e and check its flags*/
- l3p = map_domain_page(mfn_x(gw->l3mfn));
gw->l3e = l3p[guest_l3_table_offset(va)];
gflags = guest_l3e_get_flags(gw->l3e) ^ _PAGE_NX_BIT;
rc |= ((gflags & mflags) ^ mflags);
@@ -160,23 +181,14 @@ guest_walk_tables(struct vcpu *v, unsigned long va, walk_t *gw,
#endif /* PAE or 64... */
/* Map the l2 table */
- gw->l2mfn = gfn_to_mfn(d, guest_l3e_get_gfn(gw->l3e), &p2mt);
- if ( p2m_is_paging(p2mt) )
- {
- p2m_mem_paging_populate(d, gfn_x(guest_l3e_get_gfn(gw->l3e)));
-
- rc = _PAGE_PAGED;
- goto out;
- }
- if ( !p2m_is_ram(p2mt) )
- {
- rc |= _PAGE_PRESENT;
+ l2p = map_domain_gfn(d,
+ guest_l3e_get_gfn(gw->l3e),
+ &gw->l2mfn,
+ &p2mt,
+ &rc);
+ if(l2p == NULL)
goto out;
- }
- ASSERT(mfn_valid(mfn_x(gw->l2mfn)));
-
/* Get the l2e */
- l2p = map_domain_page(mfn_x(gw->l2mfn));
gw->l2e = l2p[guest_l2_table_offset(va)];
#else /* 32-bit only... */
@@ -225,21 +237,13 @@ guest_walk_tables(struct vcpu *v, unsigned long va, walk_t *gw,
else
{
/* Not a superpage: carry on and find the l1e. */
- gw->l1mfn = gfn_to_mfn(d, guest_l2e_get_gfn(gw->l2e), &p2mt);
- if ( p2m_is_paging(p2mt) )
- {
- p2m_mem_paging_populate(d, gfn_x(guest_l2e_get_gfn(gw->l2e)));
-
- rc = _PAGE_PAGED;
+ l1p = map_domain_gfn(d,
+ guest_l2e_get_gfn(gw->l2e),
+ &gw->l1mfn,
+ &p2mt,
+ &rc);
+ if(l1p == NULL)
goto out;
- }
- if ( !p2m_is_ram(p2mt) )
- {
- rc |= _PAGE_PRESENT;
- goto out;
- }
- ASSERT(mfn_valid(mfn_x(gw->l1mfn)));
- l1p = map_domain_page(mfn_x(gw->l1mfn));
gw->l1e = l1p[guest_l1_table_offset(va)];
gflags = guest_l1e_get_flags(gw->l1e) ^ _PAGE_NX_BIT;
rc |= ((gflags & mflags) ^ mflags);
diff --git a/xen/arch/x86/mm/hap/guest_walk.c b/xen/arch/x86/mm/hap/guest_walk.c
index be8a85e071..ac9b975f02 100644
--- a/xen/arch/x86/mm/hap/guest_walk.c
+++ b/xen/arch/x86/mm/hap/guest_walk.c
@@ -32,6 +32,7 @@
#if GUEST_PAGING_LEVELS <= CONFIG_PAGING_LEVELS
#include <asm/guest_pt.h>
+#include <asm/p2m.h>
unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
struct vcpu *v, unsigned long gva, uint32_t *pfec)
@@ -45,7 +46,7 @@ unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
/* Get the top-level table's MFN */
cr3 = v->arch.hvm_vcpu.guest_cr[3];
- top_mfn = gfn_to_mfn(v->domain, _gfn(cr3 >> PAGE_SHIFT), &p2mt);
+ top_mfn = gfn_to_mfn_unshare(v->domain, cr3 >> PAGE_SHIFT, &p2mt, 0);
if ( p2m_is_paging(p2mt) )
{
// if ( p2m_is_paged(p2mt) )
@@ -54,6 +55,11 @@ unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
pfec[0] = PFEC_page_paged;
return INVALID_GFN;
}
+ if ( p2m_is_shared(p2mt) )
+ {
+ pfec[0] = PFEC_page_shared;
+ return INVALID_GFN;
+ }
if ( !p2m_is_ram(p2mt) )
{
pfec[0] &= ~PFEC_page_present;
@@ -73,7 +79,7 @@ unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
if ( missing == 0 )
{
gfn_t gfn = guest_l1e_get_gfn(gw.l1e);
- gfn_to_mfn(v->domain, gfn, &p2mt);
+ gfn_to_mfn_unshare(v->domain, gfn_x(gfn), &p2mt, 0);
if ( p2m_is_paging(p2mt) )
{
// if ( p2m_is_paged(p2mt) )
@@ -82,6 +88,11 @@ unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
pfec[0] = PFEC_page_paged;
return INVALID_GFN;
}
+ if ( p2m_is_shared(p2mt) )
+ {
+ pfec[0] = PFEC_page_shared;
+ return INVALID_GFN;
+ }
return gfn_x(gfn);
}
@@ -92,6 +103,9 @@ unsigned long hap_gva_to_gfn(GUEST_PAGING_LEVELS)(
if ( missing & _PAGE_PAGED )
pfec[0] = PFEC_page_paged;
+ if ( missing & _PAGE_SHARED )
+ pfec[0] = PFEC_page_shared;
+
return INVALID_GFN;
}
diff --git a/xen/include/asm-x86/hvm/support.h b/xen/include/asm-x86/hvm/support.h
index e98daca937..6d64927868 100644
--- a/xen/include/asm-x86/hvm/support.h
+++ b/xen/include/asm-x86/hvm/support.h
@@ -74,6 +74,7 @@ enum hvm_copy_result {
HVMCOPY_bad_gfn_to_mfn,
HVMCOPY_unhandleable,
HVMCOPY_gfn_paged_out,
+ HVMCOPY_gfn_shared,
};
/*
diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h
index 9802e2d495..a94feac127 100644
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -312,6 +312,7 @@ void setup_idle_pagetable(void);
#define _PAGE_AVAIL 0xE00U
#define _PAGE_PSE_PAT 0x1000U
#define _PAGE_PAGED 0x2000U
+#define _PAGE_SHARED 0x4000U
/*
* Debug option: Ensure that granted mappings are not implicitly unmapped.
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index fc4b531022..90d8806b65 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -133,6 +133,7 @@
#define PFEC_reserved_bit (1U<<3)
#define PFEC_insn_fetch (1U<<4)
#define PFEC_page_paged (1U<<5)
+#define PFEC_page_shared (1U<<6)
#ifndef __ASSEMBLY__
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-21 03:01:53 +0000