[Xen-ia64-devel] [patch 02/16] Kexec: Unpin the correct VHPT TR in ia64_do_tlb_purge

[Simon Horman <horms@xxxxxxxxxxxx>]

When ia64_do_tlb_purge is called indrectly from play_dead()
GET_VA_VCPU_VHPT_MADDR(r2,r3) does not give the value of the VHPT
pinned into the TLB. I believe that this is because
current is changed between pinning and calling play_dead,
though I am not sure of the exact scemantics.

In any case, by recording the pinned value in a percpu variable,
and unpinning this value, the TR entry is removed and all is well.

Cc: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>

Index: xen-unstable.hg/xen/arch/ia64/linux-xen/mca_asm.S
===================================================================
--- xen-unstable.hg.orig/xen/arch/ia64/linux-xen/mca_asm.S      2008-01-25 
14:27:21.000000000 +0900
+++ xen-unstable.hg/xen/arch/ia64/linux-xen/mca_asm.S   2008-01-25 
14:39:07.000000000 +0900
@@ -326,7 +326,9 @@ ia64_do_tlb_purge:
 #ifdef XEN
        // 5. VHPT
 #if VHPT_ENABLED
-       GET_VA_VCPU_VHPT_MADDR(r2,r3);;
+       // GET_VA_VCPU_VHPT_MADDR() may not give the
+       // value of the VHPT currently pinned into the TLB
+       GET_THIS_PADDR(r2, inserted_vhpt);;
        dep r16=0,r2,0,IA64_GRANULE_SHIFT
        mov r18=IA64_GRANULE_SHIFT<<2
        ;;
Index: xen-unstable.hg/xen/arch/ia64/xen/regionreg.c
===================================================================
--- xen-unstable.hg.orig/xen/arch/ia64/xen/regionreg.c  2008-01-25 
14:33:19.000000000 +0900
+++ xen-unstable.hg/xen/arch/ia64/xen/regionreg.c       2008-01-25 
14:39:07.000000000 +0900
@@ -15,6 +15,7 @@
 #include <asm/regionreg.h>
 #include <asm/vhpt.h>
 #include <asm/vcpu.h>
+#include <asm/percpu.h>
 
 /* Defined in xemasm.S  */
 extern void ia64_new_rr7(unsigned long rid, void *shared_info, void 
*shared_arch_info, unsigned long shared_info_va, unsigned long va_vhpt);
@@ -227,6 +228,10 @@ set_rr(unsigned long rr, unsigned long r
        ia64_srlz_d();
 }
 
+#if VHPT_ENABLED
+DEFINE_PER_CPU(unsigned long, inserted_vhpt);
+#endif
+
 // validates and changes a single region register
 // in the currently executing domain
 // Passing a value of -1 is a (successful) no-op
@@ -262,6 +267,9 @@ int set_one_rr(unsigned long rr, unsigne
                if (!PSCB(v,metaphysical_mode))
                        set_rr(rr,newrrv.rrval);
        } else if (rreg == 7) {
+#if VHPT_ENABLED
+               __get_cpu_var(inserted_vhpt) = __va_ul(vcpu_vhpt_maddr(v));
+#endif
                ia64_new_rr7(vmMangleRID(newrrv.rrval),v->domain->shared_info,
                             v->arch.privregs, v->domain->arch.shared_info_va,
                             __va_ul(vcpu_vhpt_maddr(v)));

-- 

-- 
Horms


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