APIC in QEMU doesn't support x2APIC so exposing EIM is pointless and KVM
has a quirk that needs to be disabled unless we want x2APIC message with
destination 0xff to be misinterpreted as a broadcast.
Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
---
hw/i386/intel_iommu.c | 10 +++++++++-
target-i386/kvm-stub.c | 5 +++++
target-i386/kvm.c | 12 ++++++++++++
target-i386/kvm_i386.h | 1 +
4 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 28c31a2cdfa3..733751923233 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -31,6 +31,7 @@
#include "hw/i386/x86-iommu.h"
#include "hw/pci-host/q35.h"
#include "sysemu/kvm.h"
+#include "kvm_i386.h"
/*#define DEBUG_INTEL_IOMMU*/
#ifdef DEBUG_INTEL_IOMMU
@@ -2364,7 +2365,14 @@ static void vtd_init(IntelIOMMUState *s)
s->ecap = VTD_ECAP_QI | VTD_ECAP_IRO;
if (x86_iommu->intr_supported) {
- s->ecap |= VTD_ECAP_IR | VTD_ECAP_EIM | VTD_ECAP_MHMV;
+ s->ecap |= VTD_ECAP_IR | VTD_ECAP_MHMV;
+ /* QEMU APIC does not support x2APIC and KVM does not work well without
+ * disabling a quirk. IOMMU is unmigratable so we unconditionally use
+ * optional KVM features.
+ */
+ if (kvm_irqchip_in_kernel() && kvm_disable_x2apic_broadcast_quirk()) {
+ s->ecap |= VTD_ECAP_EIM;
+ }
}
vtd_reset_context_cache(s);
diff --git a/target-i386/kvm-stub.c b/target-i386/kvm-stub.c
index cdf15061091d..71be0bd94ddc 100644
--- a/target-i386/kvm-stub.c
+++ b/target-i386/kvm-stub.c
@@ -25,6 +25,11 @@ bool kvm_has_smm(void)
return 1;
}
+bool kvm_disable_x2apic_broadcast_quirk(void)
+{
+ return false;
+}
+
/* This function is only called inside conditionals which we
* rely on the compiler to optimize out when CONFIG_KVM is not
* defined.
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 0b2016a77a3c..050c850d77d3 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -128,6 +128,18 @@ bool kvm_allows_irq0_override(void)
return !kvm_irqchip_in_kernel() || kvm_has_gsi_routing();
}
+static bool kvm_x2apic_api_set_flags(uint64_t flags)
+{
+ KVMState *s = KVM_STATE(current_machine->accelerator);
+
+ return !kvm_vm_enable_cap(s, KVM_CAP_X2APIC_API, 0, flags);
+}
+
+bool kvm_disable_x2apic_broadcast_quirk(void)
+{
+ return kvm_x2apic_api_set_flags(KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK);
+}
+
static int kvm_get_tsc(CPUState *cs)
{
X86CPU *cpu = X86_CPU(cs);
diff --git a/target-i386/kvm_i386.h b/target-i386/kvm_i386.h
index 42b00af1b1c3..1bc445d59c83 100644
--- a/target-i386/kvm_i386.h
+++ b/target-i386/kvm_i386.h
@@ -41,4 +41,5 @@ int kvm_device_msix_set_vector(KVMState *s, uint32_t dev_id,
uint32_t vector,
int kvm_device_msix_assign(KVMState *s, uint32_t dev_id);
int kvm_device_msix_deassign(KVMState *s, uint32_t dev_id);
+bool kvm_disable_x2apic_broadcast_quirk(void);
#endif
--
2.9.2
