[Xen-changelog] [xen-unstable] [IA64] add seqlock to protect vtlb

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User awilliam@xxxxxxxxxxx
# Node ID 43d9c8042ab6ad02cbffd64f84782dfc9c8069ca
# Parent  bc76ad9d6270194101f3dd088b2b039532f5654f
[IA64] add seqlock to protect vtlb

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
 xen/arch/ia64/xen/domain.c    |    1 +
 xen/arch/ia64/xen/faults.c    |   10 ++++++----
 xen/arch/ia64/xen/vhpt.c      |   16 ++++++++++++++--
 xen/include/asm-ia64/domain.h |    3 +++
 4 files changed, 24 insertions(+), 6 deletions(-)

diff -r bc76ad9d6270 -r 43d9c8042ab6 xen/arch/ia64/xen/domain.c
--- a/xen/arch/ia64/xen/domain.c        Fri Jun 09 10:35:42 2006 -0600
+++ b/xen/arch/ia64/xen/domain.c        Fri Jun 09 10:35:43 2006 -0600
@@ -300,6 +300,7 @@ int arch_domain_create(struct domain *d)
        d->xen_vaend = XEN_END_ADDR;
        d->arch.shared_info_va = SHAREDINFO_ADDR;
        d->arch.breakimm = 0x1000;
+       seqlock_init(&d->arch.vtlb_lock);
 
        if (is_idle_domain(d))
            return 0;
diff -r bc76ad9d6270 -r 43d9c8042ab6 xen/arch/ia64/xen/faults.c
--- a/xen/arch/ia64/xen/faults.c        Fri Jun 09 10:35:42 2006 -0600
+++ b/xen/arch/ia64/xen/faults.c        Fri Jun 09 10:35:43 2006 -0600
@@ -214,6 +214,8 @@ void ia64_do_page_fault (unsigned long a
        // FIXME should validate address here
        unsigned long pteval;
        unsigned long is_data = !((isr >> IA64_ISR_X_BIT) & 1UL);
+       seqlock_t* vtlb_lock = &current->domain->arch.vtlb_lock;
+       unsigned long seq;
        IA64FAULT fault;
 
        if ((isr & IA64_ISR_IR) && handle_lazy_cover(current, regs)) return;
@@ -230,15 +232,15 @@ void ia64_do_page_fault (unsigned long a
        }
 
  again:
+       seq = read_seqbegin(vtlb_lock);
        fault = vcpu_translate(current,address,is_data,&pteval,&itir,&iha);
        if (fault == IA64_NO_FAULT || fault == IA64_USE_TLB) {
                u64 logps;
                pteval = translate_domain_pte(pteval, address, itir, &logps);
                vcpu_itc_no_srlz(current,is_data?2:1,address,pteval,-1UL,logps);
-               if (fault == IA64_USE_TLB && !current->arch.dtlb.pte.p) {
-                       /* dtlb has been purged in-between.  This dtlb was
-                          matching.  Undo the work.  */
-                       vcpu_flush_tlb_vhpt_range (address, 1);
+               if (read_seqretry(vtlb_lock, seq)) {
+                       vcpu_flush_tlb_vhpt_range(address & ((1 << logps) - 1),
+                                                 logps);
                        goto again;
                }
                return;
diff -r bc76ad9d6270 -r 43d9c8042ab6 xen/arch/ia64/xen/vhpt.c
--- a/xen/arch/ia64/xen/vhpt.c  Fri Jun 09 10:35:42 2006 -0600
+++ b/xen/arch/ia64/xen/vhpt.c  Fri Jun 09 10:35:43 2006 -0600
@@ -152,7 +152,9 @@ void domain_flush_vtlb_all (void)
 {
        int cpu = smp_processor_id ();
        struct vcpu *v;
-
+       seqlock_t* vtlb_lock = &current->domain->arch.vtlb_lock;
+
+       write_seqlock(vtlb_lock);
        for_each_vcpu (current->domain, v)
                if (v->processor == cpu)
                        vcpu_flush_vtlb_all ();
@@ -161,6 +163,7 @@ void domain_flush_vtlb_all (void)
                                (v->processor,
                                 (void(*)(void *))vcpu_flush_vtlb_all,
                                 NULL,1,1);
+       write_sequnlock(vtlb_lock);
 }
 
 static void cpu_flush_vhpt_range (int cpu, u64 vadr, u64 addr_range)
@@ -187,6 +190,7 @@ void vcpu_flush_tlb_vhpt_range (u64 vadr
 
 void domain_flush_vtlb_range (struct domain *d, u64 vadr, u64 addr_range)
 {
+       seqlock_t* vtlb_lock = &d->arch.vtlb_lock;
        struct vcpu *v;
 
 #if 0
@@ -197,6 +201,7 @@ void domain_flush_vtlb_range (struct dom
        }
 #endif
 
+       write_seqlock(vtlb_lock);
        for_each_vcpu (d, v) {
                /* Purge TC entries.
                   FIXME: clear only if match.  */
@@ -213,6 +218,7 @@ void domain_flush_vtlb_range (struct dom
 
        /* ptc.ga  */
        ia64_global_tlb_purge(vadr,vadr+addr_range,PAGE_SHIFT);
+       write_sequnlock(vtlb_lock);
 }
 
 static void flush_tlb_vhpt_all (struct domain *d)
@@ -224,6 +230,8 @@ static void flush_tlb_vhpt_all (struct d
        local_flush_tlb_all ();
 }
 
+// this is called when a domain is destroyed
+// so that there is no race.
 void domain_flush_destroy (struct domain *d)
 {
        /* Very heavy...  */
@@ -233,8 +241,10 @@ void domain_flush_destroy (struct domain
 
 void flush_tlb_mask(cpumask_t mask)
 {
+    seqlock_t* vtlb_lock = &current->domain->arch.vtlb_lock;
     int cpu;
 
+    write_seqlock(vtlb_lock);
     cpu = smp_processor_id();
     if (cpu_isset (cpu, mask)) {
         cpu_clear(cpu, mask);
@@ -242,11 +252,13 @@ void flush_tlb_mask(cpumask_t mask)
     }
 
     if (cpus_empty(mask))
-        return;
+        goto out;
 
     for_each_cpu_mask (cpu, mask)
         smp_call_function_single
             (cpu, (void (*)(void *))flush_tlb_vhpt_all, NULL, 1, 1);
+out:
+    write_sequnlock(vtlb_lock);
 }
 
 void zero_vhpt_stats(void)
diff -r bc76ad9d6270 -r 43d9c8042ab6 xen/include/asm-ia64/domain.h
--- a/xen/include/asm-ia64/domain.h     Fri Jun 09 10:35:42 2006 -0600
+++ b/xen/include/asm-ia64/domain.h     Fri Jun 09 10:35:43 2006 -0600
@@ -76,6 +76,9 @@ struct arch_domain {
     void *efi_runtime;
     /* Metaphysical address to fpswa_interface_t in domain firmware memory is 
set. */
     void *fpswa_inf;
+
+    // protect v->itlb, v->dtlb and vhpt
+    seqlock_t   vtlb_lock ____cacheline_aligned_in_smp;
 };
 #define xen_vastart arch.xen_vastart
 #define xen_vaend arch.xen_vaend

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