Re: [PATCH] x86/hvm: implement save/restore for posted interrupts

[Olaf Hering <olaf@aepfle.de>]

On Mon, Aug 04, Zhang, Yang Z wrote:

> This is really strange. With this patch, i cannot reproduce the issue with sles11sp3 on latest Xen. 
> 
> Besides, according the response from John, the issue they observed is exactly the eoi bitmap update issue.
> 
> BTW, my patch is based on your sync_pir_to_irr changes. I am not sure
> whether you applied the following changes when doing testing. But you
> should see the failure ratio is reduced obviously even without it,
> right?

I have used this patch now, the sync_pir_to_irr part was indeed missing.
But, still no joy for me. This is what I used:


---
 xen/arch/x86/hvm/vlapic.c        |    3 +++
 xen/arch/x86/hvm/vmx/vmx.c       |   10 ++++++++++
 xen/include/asm-x86/hvm/vlapic.h |    2 ++
 3 files changed, 15 insertions(+)

Index: xen-4.2.4-testing/xen/arch/x86/hvm/vlapic.c
===================================================================
--- xen-4.2.4-testing.orig/xen/arch/x86/hvm/vlapic.c
+++ xen-4.2.4-testing/xen/arch/x86/hvm/vlapic.c
@@ -1164,6 +1164,9 @@ static int lapic_save_regs(struct domain
 
     for_each_vcpu ( d, v )
     {
+        if ( hvm_funcs.sync_pir_to_irr )
+            hvm_funcs.sync_pir_to_irr(v);
+
         s = vcpu_vlapic(v);
         if ( (rc = hvm_save_entry(LAPIC_REGS, v->vcpu_id, h, s->regs)) != 0 )
             break;
Index: xen-4.2.4-testing/xen/arch/x86/hvm/vmx/vmx.c
===================================================================
--- xen-4.2.4-testing.orig/xen/arch/x86/hvm/vmx/vmx.c
+++ xen-4.2.4-testing/xen/arch/x86/hvm/vmx/vmx.c
@@ -1606,6 +1606,8 @@ static void vmx_process_isr(int isr, str
 {
     unsigned long status;
     u8 old;
+    int vector;
+    struct vlapic *s = vcpu_vlapic(v);
 
     if ( !cpu_has_vmx_virtual_intr_delivery )
         return;
@@ -1622,6 +1624,14 @@ static void vmx_process_isr(int isr, str
         status |= isr << VMX_GUEST_INTR_STATUS_SVI_OFFSET;
         __vmwrite(GUEST_INTR_STATUS, status);
     }
+    for ( vector = 0; vector < NR_VECTORS; vector++ )
+        if (vlapic_test_vector(vector, &s->regs->data[APIC_ISR]))
+            set_bit(vector,  v->arch.hvm_vmx.eoi_exit_bitmap);
+
+    __vmwrite(0x201c, v->arch.hvm_vmx.eoi_exit_bitmap[0]);
+    __vmwrite(0x201e, v->arch.hvm_vmx.eoi_exit_bitmap[1]);
+    __vmwrite(0x2020, v->arch.hvm_vmx.eoi_exit_bitmap[2]);
+    __vmwrite(0x2022, v->arch.hvm_vmx.eoi_exit_bitmap[3]);
     vmx_vmcs_exit(v);
 }
 
Index: xen-4.2.4-testing/xen/include/asm-x86/hvm/vlapic.h
===================================================================
--- xen-4.2.4-testing.orig/xen/include/asm-x86/hvm/vlapic.h
+++ xen-4.2.4-testing/xen/include/asm-x86/hvm/vlapic.h
@@ -60,6 +60,8 @@
 
 #define VEC_POS(v) ((v) % 32)
 #define REG_POS(v) (((v) / 32) * 0x10)
+#define vlapic_test_vector(vec, bitmap)                         \
+    test_bit(VEC_POS(vec), (uint32_t *)((bitmap) + REG_POS(vec)))
 #define vlapic_test_and_set_vector(vec, bitmap)                         \
     test_and_set_bit(VEC_POS(vec), (uint32_t *)((bitmap) + REG_POS(vec)))
 #define vlapic_test_and_clear_vector(vec, bitmap)                       \


Olaf