|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 (resend) 07/27] x86: Map/unmap pages in restore_all_guests
From: Hongyan Xia <hongyxia@xxxxxxxxxx>
Before, it assumed the pv cr3 could be accessed via a direct map. This
is no longer true.
Note that we do not map and unmap root_pgt for now since it is still a
xenheap page.
Signed-off-by: Hongyan Xia <hongyxia@xxxxxxxxxx>
Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
Signed-off-by: Elias El Yandouzi <eliasely@xxxxxxxxxx>
----
Changes in V2:
* Rework the shadow perdomain mapping solution in the follow-up patches
Changes since Hongyan's version:
* Remove the final dot in the commit title
diff --git a/xen/arch/x86/include/asm/config.h
b/xen/arch/x86/include/asm/config.h
index bbced338be..7cf1f33dc0 100644
--- a/xen/arch/x86/include/asm/config.h
+++ b/xen/arch/x86/include/asm/config.h
@@ -202,7 +202,7 @@ extern unsigned char boot_edid_info[128];
/* Slot 260: per-domain mappings (including map cache). */
#define PERDOMAIN_VIRT_START (PML4_ADDR(260))
#define PERDOMAIN_SLOT_MBYTES (PML4_ENTRY_BYTES >> (20 + PAGETABLE_ORDER))
-#define PERDOMAIN_SLOTS 3
+#define PERDOMAIN_SLOTS 4
#define PERDOMAIN_VIRT_SLOT(s) (PERDOMAIN_VIRT_START + (s) * \
(PERDOMAIN_SLOT_MBYTES << 20))
/* Slot 4: mirror of per-domain mappings (for compat xlat area accesses). */
@@ -316,6 +316,16 @@ extern unsigned long xen_phys_start;
#define ARG_XLAT_START(v) \
(ARG_XLAT_VIRT_START + ((v)->vcpu_id << ARG_XLAT_VA_SHIFT))
+/* root_pt shadow mapping area. The fourth per-domain-mapping sub-area */
+#define SHADOW_ROOT_PT_VIRT_START PERDOMAIN_VIRT_SLOT(3)
+#define SHADOW_ROOT_PT_ENTRIES MAX_VIRT_CPUS
+#define SHADOW_ROOT_PT_VIRT_END (SHADOW_ROOT_PT_VIRT_START + \
+ (SHADOW_ROOT_PT_ENTRIES * PAGE_SIZE))
+
+/* The address of a particular VCPU's ROOT_PT */
+#define SHADOW_ROOT_PT_VCPU_VIRT_START(v) \
+ (SHADOW_ROOT_PT_VIRT_START + ((v)->vcpu_id * PAGE_SIZE))
+
#define ELFSIZE 64
#define ARCH_CRASH_SAVE_VMCOREINFO
diff --git a/xen/arch/x86/include/asm/domain.h
b/xen/arch/x86/include/asm/domain.h
index 622d22bef2..4d97c68028 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -273,6 +273,7 @@ struct time_scale {
struct pv_domain
{
l1_pgentry_t **gdt_ldt_l1tab;
+ l1_pgentry_t **shadow_root_pt_l1tab;
atomic_t nr_l4_pages;
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index b56e0d8065..a72c32d87c 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -505,6 +505,13 @@ void share_xen_page_with_guest(struct page_info *page,
struct domain *d,
spin_unlock(&d->page_alloc_lock);
}
+#define shadow_root_pt_idx(v) \
+ ((v)->vcpu_id >> PAGETABLE_ORDER)
+
+#define pv_shadow_root_pt_pte(v) \
+ ((v)->domain->arch.pv.shadow_root_pt_l1tab[shadow_root_pt_idx(v)] + \
+ ((v)->vcpu_id & (L1_PAGETABLE_ENTRIES - 1)))
+
void make_cr3(struct vcpu *v, mfn_t mfn)
{
struct domain *d = v->domain;
@@ -524,6 +531,13 @@ void write_ptbase(struct vcpu *v)
if ( is_pv_vcpu(v) && v->domain->arch.pv.xpti )
{
+ mfn_t guest_root_pt = _mfn(v->arch.cr3 >> PAGE_SHIFT);
+ l1_pgentry_t *pte = pv_shadow_root_pt_pte(v);
+
+ ASSERT(v == current);
+
+ l1e_write(pte, l1e_from_mfn(guest_root_pt, __PAGE_HYPERVISOR_RW));
+
cpu_info->root_pgt_changed = true;
cpu_info->pv_cr3 = __pa(this_cpu(root_pgt));
if ( new_cr4 & X86_CR4_PCIDE )
diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index 2a445bb17b..fef9ae2352 100644
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -288,6 +288,19 @@ static void pv_destroy_gdt_ldt_l1tab(struct vcpu *v)
1U << GDT_LDT_VCPU_SHIFT);
}
+static int pv_create_shadow_root_pt_l1tab(struct vcpu *v)
+{
+ return create_perdomain_mapping(v->domain,
SHADOW_ROOT_PT_VCPU_VIRT_START(v),
+ 1, v->domain->arch.pv.shadow_root_pt_l1tab,
+ NULL);
+}
+
+static void pv_destroy_shadow_root_pt_l1tab(struct vcpu *v)
+
+{
+ destroy_perdomain_mapping(v->domain, SHADOW_ROOT_PT_VCPU_VIRT_START(v), 1);
+}
+
void pv_vcpu_destroy(struct vcpu *v)
{
if ( is_pv_32bit_vcpu(v) )
@@ -297,6 +310,7 @@ void pv_vcpu_destroy(struct vcpu *v)
}
pv_destroy_gdt_ldt_l1tab(v);
+ pv_destroy_shadow_root_pt_l1tab(v);
XFREE(v->arch.pv.trap_ctxt);
}
@@ -311,6 +325,13 @@ int pv_vcpu_initialise(struct vcpu *v)
if ( rc )
return rc;
+ if ( v->domain->arch.pv.xpti )
+ {
+ rc = pv_create_shadow_root_pt_l1tab(v);
+ if ( rc )
+ goto done;
+ }
+
BUILD_BUG_ON(X86_NR_VECTORS * sizeof(*v->arch.pv.trap_ctxt) >
PAGE_SIZE);
v->arch.pv.trap_ctxt = xzalloc_array(struct trap_info, X86_NR_VECTORS);
@@ -346,10 +367,12 @@ void pv_domain_destroy(struct domain *d)
destroy_perdomain_mapping(d, GDT_LDT_VIRT_START,
GDT_LDT_MBYTES << (20 - PAGE_SHIFT));
+ destroy_perdomain_mapping(d, SHADOW_ROOT_PT_VIRT_START,
SHADOW_ROOT_PT_ENTRIES);
XFREE(d->arch.pv.cpuidmasks);
FREE_XENHEAP_PAGE(d->arch.pv.gdt_ldt_l1tab);
+ FREE_XENHEAP_PAGE(d->arch.pv.shadow_root_pt_l1tab);
}
void noreturn cf_check continue_pv_domain(void);
@@ -371,6 +394,12 @@ int pv_domain_initialise(struct domain *d)
goto fail;
clear_page(d->arch.pv.gdt_ldt_l1tab);
+ d->arch.pv.shadow_root_pt_l1tab =
+ alloc_xenheap_pages(0, MEMF_node(domain_to_node(d)));
+ if ( !d->arch.pv.shadow_root_pt_l1tab )
+ goto fail;
+ clear_page(d->arch.pv.shadow_root_pt_l1tab);
+
if ( levelling_caps & ~LCAP_faulting &&
(d->arch.pv.cpuidmasks = xmemdup(&cpuidmask_defaults)) == NULL )
goto fail;
@@ -381,6 +410,11 @@ int pv_domain_initialise(struct domain *d)
if ( rc )
goto fail;
+ rc = create_perdomain_mapping(d, SHADOW_ROOT_PT_VIRT_START,
+ SHADOW_ROOT_PT_ENTRIES, NULL, NULL);
+ if ( rc )
+ goto fail;
+
d->arch.ctxt_switch = &pv_csw;
d->arch.pv.xpti = is_hardware_domain(d) ? opt_xpti_hwdom : opt_xpti_domu;
diff --git a/xen/arch/x86/x86_64/asm-offsets.c
b/xen/arch/x86/x86_64/asm-offsets.c
index 57b73a4e62..23f9cca1a2 100644
--- a/xen/arch/x86/x86_64/asm-offsets.c
+++ b/xen/arch/x86/x86_64/asm-offsets.c
@@ -51,6 +51,7 @@ void __dummy__(void)
OFFSET(UREGS_kernel_sizeof, struct cpu_user_regs, es);
BLANK();
+ OFFSET(VCPU_id, struct vcpu, vcpu_id);
OFFSET(VCPU_processor, struct vcpu, processor);
OFFSET(VCPU_domain, struct vcpu, domain);
OFFSET(VCPU_vcpu_info, struct vcpu, vcpu_info_area.map);
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index c25b14dde6..a216c5ca7a 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -165,7 +165,15 @@ restore_all_guest:
and %rsi, %rdi
and %r9, %rsi
add %rcx, %rdi
+
+ /*
+ * The address in the vCPU cr3 is always mapped in the shadow
+ * root_pt virt area.
+ */
+ imul $PAGE_SIZE, VCPU_id(%rbx), %esi
+ movabs $SHADOW_ROOT_PT_VIRT_START, %rcx
add %rcx, %rsi
+
mov $ROOT_PAGETABLE_FIRST_XEN_SLOT, %ecx
mov root_table_offset(SH_LINEAR_PT_VIRT_START)*8(%rsi), %r8
mov %r8, root_table_offset(SH_LINEAR_PT_VIRT_START)*8(%rdi)
--
2.40.1
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |