[Xen-changelog] [xen stable-4.2] x86/HVM: fix x2APIC APIC_ID read emulation

[patchbot@xxxxxxx]

commit a0c56a2b9f5b3232ee83618bd82eb0439e30d2be
Author:     Zhenguo Wang <wangzhenguo@xxxxxxxxxx>
AuthorDate: Mon Jul 1 11:58:26 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Jul 1 11:58:26 2013 +0200

    x86/HVM: fix x2APIC APIC_ID read emulation
    
    APIC and x2APIC have different format for APIC_ID register. Need
    translation.
    
    Signed-off-by: Zhenguo Wang <wangzhenguo@xxxxxxxxxx>
    Signed-off-by: Xiaowei Yang <xiaowei.yang@xxxxxxxxxx>
    
    Convert code to use switch(), fixing coding style issue at once, and
    use GET_xAPIC_ID() on the value read instead of VLAPIC_ID() (reading
    the field again).
    
    In the course of this also properly reject both read and writes on the
    non-existing MSR corresponding to APIC_ICR2.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Keir Fraser <keir@xxxxxxx>
    master commit: 6859874b61d5ddaf5289e72ed2b2157739b72ca5
    master date: 2013-06-11 09:45:55 +0200
---
 xen/arch/x86/hvm/vlapic.c |   23 ++++++++++++++++++++---
 1 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 7778342..f3833be 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -583,8 +583,19 @@ int hvm_x2apic_msr_read(struct vcpu *v, unsigned int msr, 
uint64_t *msr_content)
         return 1;
 
     vlapic_read_aligned(vlapic, offset, &low);
-    if ( offset == APIC_ICR )
+    switch ( offset )
+    {
+    case APIC_ID:
+        low = GET_xAPIC_ID(low);
+        break;
+
+    case APIC_ICR:
         vlapic_read_aligned(vlapic, APIC_ICR2, &high);
+        break;
+
+    case APIC_ICR2:
+        return 1;
+    }
 
     *msr_content = (((uint64_t)high) << 32) | low;
     return 0;
@@ -833,11 +844,17 @@ int hvm_x2apic_msr_write(struct vcpu *v, unsigned int 
msr, uint64_t msr_content)
     if ( !vlapic_x2apic_mode(vlapic) )
         return X86EMUL_UNHANDLEABLE;
 
-    if ( offset == APIC_ICR )
+    switch ( offset )
     {
-        int rc = vlapic_reg_write(v, APIC_ICR2, (uint32_t)(msr_content >> 32));
+        int rc;
+
+    case APIC_ICR:
+        rc = vlapic_reg_write(v, APIC_ICR2, (uint32_t)(msr_content >> 32));
         if ( rc )
             return rc;
+
+    case APIC_ICR2:
+        return X86EMUL_UNHANDLEABLE;
     }
 
     return vlapic_reg_write(v, offset, (uint32_t)msr_content);
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.2

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