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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH RFC 39/55] x86: switch root_pgt to mfn_t and use new APIs
This then requires moving declaration of root page table mfn into mm.h
and modify setup_cpu_root_pgt to have a single exit path.
We also need to force map_domain_page to use direct map when switching
per-domain mappings. This is contrary to our end goal of removing
direct map, but this will be removed once we make map_domain_page
context-switch safe in another (large) patch series.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
xen/arch/x86/domain.c | 15 ++++++++++++---
xen/arch/x86/domain_page.c | 2 +-
xen/arch/x86/mm.c | 2 +-
xen/arch/x86/pv/domain.c | 2 +-
xen/arch/x86/smpboot.c | 40 +++++++++++++++++++++++++++-------------
xen/include/asm-x86/mm.h | 2 ++
xen/include/asm-x86/processor.h | 1 -
7 files changed, 44 insertions(+), 20 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 32dc4253ff..603495e55a 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -68,6 +68,7 @@
#include <asm/pv/domain.h>
#include <asm/pv/mm.h>
#include <asm/spec_ctrl.h>
+#include <asm/setup.h>
DEFINE_PER_CPU(struct vcpu *, curr_vcpu);
@@ -1589,12 +1590,20 @@ void paravirt_ctxt_switch_from(struct vcpu *v)
void paravirt_ctxt_switch_to(struct vcpu *v)
{
- root_pgentry_t *root_pgt = this_cpu(root_pgt);
+ mfn_t rpt_mfn = this_cpu(root_pgt_mfn);
- if ( root_pgt )
- root_pgt[root_table_offset(PERDOMAIN_VIRT_START)] =
+ if ( !mfn_eq(rpt_mfn, INVALID_MFN) )
+ {
+ root_pgentry_t *rpt;
+
+ mapcache_override_current(INVALID_VCPU);
+ rpt = map_xen_pagetable_new(rpt_mfn);
+ rpt[root_table_offset(PERDOMAIN_VIRT_START)] =
l4e_from_page(v->domain->arch.perdomain_l3_pg,
__PAGE_HYPERVISOR_RW);
+ UNMAP_XEN_PAGETABLE_NEW(rpt);
+ mapcache_override_current(NULL);
+ }
if ( unlikely(v->arch.dr7 & DR7_ACTIVE_MASK) )
activate_debugregs(v);
diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index 24083e9a86..cfcffd35f3 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -57,7 +57,7 @@ static inline struct vcpu *mapcache_current_vcpu(void)
return v;
}
-void __init mapcache_override_current(struct vcpu *v)
+void mapcache_override_current(struct vcpu *v)
{
this_cpu(override) = v;
}
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 9e115ef0b8..44c9df5c9e 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -564,7 +564,7 @@ void write_ptbase(struct vcpu *v)
if ( is_pv_vcpu(v) && v->domain->arch.pv.xpti )
{
cpu_info->root_pgt_changed = true;
- cpu_info->pv_cr3 = __pa(this_cpu(root_pgt));
+ cpu_info->pv_cr3 = mfn_to_maddr(this_cpu(root_pgt_mfn));
if ( new_cr4 & X86_CR4_PCIDE )
cpu_info->pv_cr3 |= get_pcid_bits(v, true);
switch_cr3_cr4(v->arch.cr3, new_cr4);
diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index 7e84b04082..2fd944b7e3 100644
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -303,7 +303,7 @@ static void _toggle_guest_pt(struct vcpu *v)
struct cpu_info *cpu_info = get_cpu_info();
cpu_info->root_pgt_changed = true;
- cpu_info->pv_cr3 = __pa(this_cpu(root_pgt)) |
+ cpu_info->pv_cr3 = mfn_to_maddr(this_cpu(root_pgt_mfn)) |
(d->arch.pv.pcid ? get_pcid_bits(v, true) : 0);
}
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index a9a39cea6e..32dce00d10 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -819,7 +819,7 @@ static int clone_mapping(const void *ptr, root_pgentry_t
*rpt)
return rc;
}
-DEFINE_PER_CPU(root_pgentry_t *, root_pgt);
+DEFINE_PER_CPU(mfn_t, root_pgt_mfn);
static root_pgentry_t common_pgt;
@@ -827,19 +827,27 @@ extern const char _stextentry[], _etextentry[];
static int setup_cpu_root_pgt(unsigned int cpu)
{
- root_pgentry_t *rpt;
+ root_pgentry_t *rpt = NULL;
+ mfn_t rpt_mfn;
unsigned int off;
int rc;
if ( !opt_xpti_hwdom && !opt_xpti_domu )
- return 0;
+ {
+ rc = 0;
+ goto out;
+ }
- rpt = alloc_xen_pagetable();
- if ( !rpt )
- return -ENOMEM;
+ rpt_mfn = alloc_xen_pagetable_new();
+ if ( mfn_eq(rpt_mfn, INVALID_MFN) )
+ {
+ rc = -ENOMEM;
+ goto out;
+ }
+ rpt = map_xen_pagetable_new(rpt_mfn);
clear_page(rpt);
- per_cpu(root_pgt, cpu) = rpt;
+ per_cpu(root_pgt_mfn, cpu) = rpt_mfn;
rpt[root_table_offset(RO_MPT_VIRT_START)] =
idle_pg_table[root_table_offset(RO_MPT_VIRT_START)];
@@ -856,7 +864,7 @@ static int setup_cpu_root_pgt(unsigned int cpu)
rc = clone_mapping(ptr, rpt);
if ( rc )
- return rc;
+ goto out;
common_pgt = rpt[root_table_offset(XEN_VIRT_START)];
}
@@ -875,19 +883,24 @@ static int setup_cpu_root_pgt(unsigned int cpu)
if ( !rc )
rc = clone_mapping((void *)per_cpu(stubs.addr, cpu), rpt);
+ out:
+ UNMAP_XEN_PAGETABLE_NEW(rpt);
return rc;
}
static void cleanup_cpu_root_pgt(unsigned int cpu)
{
- root_pgentry_t *rpt = per_cpu(root_pgt, cpu);
+ mfn_t rpt_mfn = per_cpu(root_pgt_mfn, cpu);
+ root_pgentry_t *rpt;
unsigned int r;
unsigned long stub_linear = per_cpu(stubs.addr, cpu);
- if ( !rpt )
+ if ( mfn_eq(rpt_mfn, INVALID_MFN) )
return;
- per_cpu(root_pgt, cpu) = NULL;
+ per_cpu(root_pgt_mfn, cpu) = INVALID_MFN;
+
+ rpt = map_xen_pagetable_new(rpt_mfn);
for ( r = root_table_offset(DIRECTMAP_VIRT_START);
r < root_table_offset(HYPERVISOR_VIRT_END); ++r )
@@ -932,7 +945,8 @@ static void cleanup_cpu_root_pgt(unsigned int cpu)
free_xen_pagetable_new(l3t_mfn);
}
- free_xen_pagetable(rpt);
+ UNMAP_XEN_PAGETABLE_NEW(rpt);
+ free_xen_pagetable_new(rpt_mfn);
/* Also zap the stub mapping for this CPU. */
if ( stub_linear )
@@ -1138,7 +1152,7 @@ void __init smp_prepare_cpus(void)
rc = setup_cpu_root_pgt(0);
if ( rc )
panic("Error %d setting up PV root page table\n", rc);
- if ( per_cpu(root_pgt, 0) )
+ if ( !mfn_eq(per_cpu(root_pgt_mfn, 0), INVALID_MFN) )
{
get_cpu_info()->pv_cr3 = 0;
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 4378d9f815..708b84bb89 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -657,4 +657,6 @@ void free_xen_pagetable_new(mfn_t mfn);
l1_pgentry_t *virt_to_xen_l1e(unsigned long v);
+DECLARE_PER_CPU(mfn_t, root_pgt_mfn);
+
#endif /* __ASM_X86_MM_H__ */
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index df01ae30d7..9f98ac96f5 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -449,7 +449,6 @@ extern idt_entry_t idt_table[];
extern idt_entry_t *idt_tables[];
DECLARE_PER_CPU(struct tss_struct, init_tss);
-DECLARE_PER_CPU(root_pgentry_t *, root_pgt);
extern void write_ptbase(struct vcpu *v);
--
2.11.0
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