[Xen-changelog] [xen master] VMX: fix interaction of APIC-V and Viridian emulation

[patchbot@xxxxxxx]

commit 303066fdb1e4fe816e48acd665453f58b8399e81
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Jul 17 08:47:18 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Jul 17 08:47:18 2013 +0200

    VMX: fix interaction of APIC-V and Viridian emulation
    
    Viridian using a synthetic MSR for issuing EOI notifications bypasses
    the normal in-processor handling, which would clear
    GUEST_INTR_STATUS.SVI. Hence we need to do this in software in order
    for future interrupts to get delivered.
    
    Based on analysis by Yang Z Zhang <yang.z.zhang@xxxxxxxxx>.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Yang Zhang <yang.z.zhang@xxxxxxxxx>
---
 xen/arch/x86/hvm/vlapic.c     |    3 +++
 xen/arch/x86/hvm/vmx/vmx.c    |   15 ++++++++++++++-
 xen/include/asm-x86/hvm/hvm.h |    1 +
 3 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index e039ed0..7a154f9 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -386,6 +386,9 @@ void vlapic_EOI_set(struct vlapic *vlapic)
 
     vlapic_clear_vector(vector, &vlapic->regs->data[APIC_ISR]);
 
+    if ( hvm_funcs.handle_eoi )
+        hvm_funcs.handle_eoi(vector);
+
     if ( vlapic_test_and_clear_vector(vector, &vlapic->regs->data[APIC_TMR]) )
         vioapic_update_EOI(vlapic_domain(vlapic), vector);
 
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index d6540e3..24098e4 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1505,6 +1505,15 @@ static void vmx_sync_pir_to_irr(struct vcpu *v)
         vlapic_set_vector(i, &vlapic->regs->data[APIC_IRR]);
 }
 
+static void vmx_handle_eoi(u8 vector)
+{
+    unsigned long status = __vmread(GUEST_INTR_STATUS);
+
+    /* We need to clear the SVI field. */
+    status &= VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK;
+    __vmwrite(GUEST_INTR_STATUS, status);
+}
+
 static struct hvm_function_table __initdata vmx_function_table = {
     .name                 = "VMX",
     .cpu_up_prepare       = vmx_cpu_up_prepare,
@@ -1557,6 +1566,7 @@ static struct hvm_function_table __initdata 
vmx_function_table = {
     .process_isr          = vmx_process_isr,
     .deliver_posted_intr  = vmx_deliver_posted_intr,
     .sync_pir_to_irr      = vmx_sync_pir_to_irr,
+    .handle_eoi           = vmx_handle_eoi,
     .nhvm_hap_walk_L1_p2m = nvmx_hap_walk_L1_p2m,
 };
 
@@ -1583,7 +1593,10 @@ const struct hvm_function_table * __init start_vmx(void)
 
         setup_ept_dump();
     }
- 
+
+    if ( !cpu_has_vmx_virtual_intr_delivery )
+        vmx_function_table.handle_eoi = NULL;
+
     if ( cpu_has_vmx_posted_intr_processing )
         alloc_direct_apic_vector(&posted_intr_vector, event_check_interrupt);
     else
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 8408420..00489cf 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -186,6 +186,7 @@ struct hvm_function_table {
     void (*process_isr)(int isr, struct vcpu *v);
     void (*deliver_posted_intr)(struct vcpu *v, u8 vector);
     void (*sync_pir_to_irr)(struct vcpu *v);
+    void (*handle_eoi)(u8 vector);
 
     /*Walk nested p2m  */
     int (*nhvm_hap_walk_L1_p2m)(struct vcpu *v, paddr_t L2_gpa,
--
generated by git-patchbot for /home/xen/git/xen.git#master

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