[Xen-changelog] [xen staging] x86/vvmx: virtualize x2APIC mode and APIC accesses can't both be enabled

[patchbot@xxxxxxx]

commit da9290639eb5d6ac9d77d577927b6e69c8ca9e21
Author:     Roger Pau Monne <roger.pau@xxxxxxxxxx>
AuthorDate: Tue Dec 24 16:32:47 2019 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Dec 26 15:57:04 2019 +0000

    x86/vvmx: virtualize x2APIC mode and APIC accesses can't both be enabled
    
    According to the Intel SDM, "virtualize x2APIC mode" and "virtualize
    APIC accesses" can't be enabled at the same time, or else a
    vm{launch/entry} failure will happen. This was seen when running Xen
    nested and with x2APIC enabled:
    
      (XEN) d3v0 VMLAUNCH error: 0x7
      [...]
      (XEN) *** Control State ***
      (XEN) PinBased=0000003f CPUBased=b6a075fe SecondaryExec=000014fb
      [...]
    
    Fix this by making sure nvmx_update_secondary_exec_control clears the
    incompatible bits from the host vmcs before merging it with the nested
    vmcs.
    
    This fixes a regression reported by osstest in the
    test-amd64-amd64-qemuu-nested-intel job.
    
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vvmx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 5dd00e11b5..d8ab167d62 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -594,6 +594,7 @@ void nvmx_update_secondary_exec_control(struct vcpu *v,
     u32 shadow_cntrl;
     struct nestedvmx *nvmx = &vcpu_2_nvmx(v);
     u32 apicv_bit = SECONDARY_EXEC_APIC_REGISTER_VIRT |
+                    SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                     SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY;
 
     host_cntrl &= ~apicv_bit;
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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