Attachment 314114 Details for Bug 457137 – proposed patch. revised to apply to kernel.

[patch] proposed patch. revised to apply to kernel.

xen-ia64-fix-smp-unsafe-with-XENMEM_add_to_physmap-on-hvm.patch (text/plain), 3.77 KB, created by Tetsu Yamamoto on 2008-08-12 16:54:33 UTC

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Creator: Tetsu Yamamoto

Created: 2008-08-12 16:54:33 UTC

Size: 3.77 KB

patch

obsolete

># HG changeset patch
># User Isaku Yamahata <yamahata@valinux.co.jp>
># Date 1215484903 -32400
># Node ID eb0fc71cfc72ed15ed35fa17617b7cab32164029
># Parent  00721ef8d8ef3fee031faf974682ba91c5d67ef6
>[IA64] Fix SMP-unsafe with XENMEM_add_to_physmap on HVM
>
>XENMEM_add_to_physmap hypercall on HVM is SMP-unsafe
>and may cause a xen crash.
>Actually I've met:
>
>(XEN) ia64_fault, vector=0x18, ifa=0xe0000165c98814f0, iip=0xf0000000040a1b80, ipsr=0x0000121008226010, isr=0x0000008000000030
>(XEN) General Exception: IA-64 Reserved Register/Field fault (data access).
>...
>(XEN) ****************************************
>(XEN) Panic on CPU 2:
>(XEN) Fault in Xen.
>(XEN) ****************************************
>
>This patch fixes it.
>
>Signed-off-by: Kouya Shimura <kouya@jp.fujitsu.com>
>
>Index: xen/arch/ia64/vmx/vtlb.c
>===================================================================
>--- xen.orig/arch/ia64/vmx/vtlb.c
>+++ xen/arch/ia64/vmx/vtlb.c
>@@ -619,6 +619,30 @@ void thash_purge_all(VCPU *v)
>     local_flush_tlb_all();
> }
> 
>+static void __thash_purge_all(void *arg)
>+{
>+    struct vcpu *v = arg;
>+
>+    BUG_ON(vcpu_runnable(v) || v->is_running);
>+    thash_purge_all(v);
>+}
>+
>+void vmx_vcpu_flush_vtlb_all(VCPU *v)
>+{
>+    if (v == current) {
>+        thash_purge_all(v);
>+        return;
>+    }
>+
>+    /* SMP safe */
>+    vcpu_pause(v);
>+    if (v->processor == smp_processor_id())
>+        __thash_purge_all(v);
>+    else
>+        smp_call_function_single(v->processor, __thash_purge_all, v, 1, 1);
>+    vcpu_unpause(v);
>+}
>+
> 
> /*
>  * Lookup the hash table and its collision chain to find an entry
>Index: xen/arch/ia64/xen/vhpt.c
>===================================================================
>--- xen.orig/arch/ia64/xen/vhpt.c
>+++ xen/arch/ia64/xen/vhpt.c
>@@ -220,31 +220,20 @@ domain_purge_swtc_entries_vcpu_dirty_mas
> // (e.g. vcpu == current), smp_mb() is unnecessary.
> void vcpu_flush_vtlb_all(struct vcpu *v)
> {
>-	if (VMX_DOMAIN(v)) {
>-		/* This code may be call for remapping shared_info and
>-		   grant_table share page from guest_physmap_remove_page()
>-		   in arch_memory_op() XENMEM_add_to_physmap to realize
>-		   PV-on-HVM feature. */
>-		/* FIXME: This is not SMP-safe yet about p2m table */
>-		/* Purge vTLB for VT-i domain */
>-		thash_purge_all(v);
>-	}
>-	else {
>-		/* First VCPU tlb.  */
>-		vcpu_purge_tr_entry(&PSCBX(v,dtlb));
>-		vcpu_purge_tr_entry(&PSCBX(v,itlb));
>-		smp_mb();
>-
>-		/* Then VHPT.  */
>-		if (HAS_PERVCPU_VHPT(v->domain))
>-			vcpu_vhpt_flush(v);
>-		else
>-			local_vhpt_flush();
>-		smp_mb();
>+	/* First VCPU tlb.  */
>+	vcpu_purge_tr_entry(&PSCBX(v,dtlb));
>+	vcpu_purge_tr_entry(&PSCBX(v,itlb));
>+	smp_mb();
> 
>-		/* Then mTLB.  */
>-		local_flush_tlb_all();
>-	}
>+	/* Then VHPT.  */
>+	if (HAS_PERVCPU_VHPT(v->domain))
>+		vcpu_vhpt_flush(v);
>+	else
>+		local_vhpt_flush();
>+	smp_mb();
>+
>+	/* Then mTLB.  */
>+	local_flush_tlb_all();
> 
> 	/* We could clear bit in d->domain_dirty_cpumask only if domain d in
> 	   not running on this processor.  There is currently no easy way to
>@@ -268,6 +257,15 @@ void domain_flush_vtlb_all(struct domain
> 		if (!v->is_initialised)
> 			continue;
> 
>+		if (VMX_DOMAIN(v)) {
>+			// This code may be called for remapping shared_info
>+			// and grant_table from guest_physmap_remove_page()
>+			// in arch_memory_op() XENMEM_add_to_physmap to realize
>+			// PV-on-HVM feature.
>+			vmx_vcpu_flush_vtlb_all(v);
>+			continue;
>+		}
>+
> 		if (v->processor == cpu)
> 			vcpu_flush_vtlb_all(v);
> 		else
>Index: xen/include/asm-ia64/vmmu.h
>===================================================================
>--- xen.orig/include/asm-ia64/vmmu.h
>+++ xen/include/asm-ia64/vmmu.h
>@@ -277,6 +277,7 @@ extern void thash_purge_and_insert(struc
>  *
>  */
> extern void thash_purge_all(struct vcpu *v);
>+extern void vmx_vcpu_flush_vtlb_all(struct vcpu *v);
> 
> /*
>  * Lookup the hash table and its collision chain to find an entry

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Attachments on bug 457137: 312930 | 314114