[Xen-devel] [PATCH 1/2] nvmx: fix handling of interrupts

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

When doing a virtual vmexit (ie: a vmexit handled by the L1 VMM)
interrupts shouldn't be injected using the virtual interrupt delivery
mechanism, and instead should be signaled in the vmcs using the exit
reason and the interruption-information field if the "Acknowledge
interrupt on exit" vmexit control is set.

Remove the nvmx_update_apicv helper: it's bogus to attempt to inject
interrupts on virtual vmexit using the virtual interrupt delivery
assistance, and it's also bogus to ack interrupts without checking if
the vmexit "Acknowledge interrupt on exit" vmexit control is set.
nvmx_intr_intercept already handles interrupts correctly on virtual
vmexit.

Note that this fixes the usage of x2APIC by the L1 VMM, at least when
the L1 VMM is Xen.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vvmx.c | 32 --------------------------------
 1 file changed, 32 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index d8ab167d62..af48b0beef 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -1316,35 +1316,6 @@ static void sync_exception_state(struct vcpu *v)
     }
 }
 
-static void nvmx_update_apicv(struct vcpu *v)
-{
-    struct nestedvmx *nvmx = &vcpu_2_nvmx(v);
-    unsigned long reason = get_vvmcs(v, VM_EXIT_REASON);
-    uint32_t intr_info = get_vvmcs(v, VM_EXIT_INTR_INFO);
-
-    if ( reason == EXIT_REASON_EXTERNAL_INTERRUPT &&
-         nvmx->intr.source == hvm_intsrc_lapic &&
-         (intr_info & INTR_INFO_VALID_MASK) )
-    {
-        uint16_t status;
-        uint32_t rvi, ppr;
-        uint32_t vector = intr_info & 0xff;
-        struct vlapic *vlapic = vcpu_vlapic(v);
-
-        vlapic_ack_pending_irq(v, vector, 1);
-
-        ppr = vlapic_set_ppr(vlapic);
-        WARN_ON((ppr & 0xf0) != (vector & 0xf0));
-
-        status = vector << VMX_GUEST_INTR_STATUS_SVI_OFFSET;
-        rvi = vlapic_has_pending_irq(v);
-        if ( rvi != -1 )
-            status |= rvi & VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK;
-
-        __vmwrite(GUEST_INTR_STATUS, status);
-    }
-}
-
 static void virtual_vmexit(struct cpu_user_regs *regs)
 {
     struct vcpu *v = current;
@@ -1393,9 +1364,6 @@ static void virtual_vmexit(struct cpu_user_regs *regs)
     /* updating host cr0 to sync TS bit */
     __vmwrite(HOST_CR0, v->arch.hvm.vmx.host_cr0);
 
-    if ( cpu_has_vmx_virtual_intr_delivery )
-        nvmx_update_apicv(v);
-
     nvcpu->nv_vmswitch_in_progress = 0;
 }
 
-- 
2.24.1


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