diff mbox

[v3,7/8] intel_iommu: keep buggy EIM enabled in 2.7 machine type

Message ID 20160930161013.9832-8-rkrcmar@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Radim Krčmář Sept. 30, 2016, 4:10 p.m. UTC
QEMU 2.7 allowed EIM even in configurations that were forbidden in the
last patch because they were not working, like old KVM or userspace
APIC.  In order to keep backward compatibility, we again allow guests to
misbehave in non-obvious ways, and make it the default.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
v3: shorten the code [Peter]
---
 hw/i386/intel_iommu.c | 12 +++++++-----
 hw/i386/pc_q35.c      |  2 ++
 include/hw/i386/pc.h  |  2 ++
 3 files changed, 11 insertions(+), 5 deletions(-)

Comments

Igor Mammedov Oct. 4, 2016, 12:18 p.m. UTC | #1
On Fri, 30 Sep 2016 18:10:12 +0200
Radim Krčmář <rkrcmar@redhat.com> wrote:

> QEMU 2.7 allowed EIM even in configurations that were forbidden in the
> last patch because they were not working, like old KVM or userspace
> APIC.  In order to keep backward compatibility, we again allow guests to
> misbehave in non-obvious ways, and make it the default.
> 
> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
> ---
> v3: shorten the code [Peter]
> ---
>  hw/i386/intel_iommu.c | 12 +++++++-----
>  hw/i386/pc_q35.c      |  2 ++
>  include/hw/i386/pc.h  |  2 ++
>  3 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index efb018b85544..13a2ac5a8fb9 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -2456,9 +2456,11 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &vtd_as->as;
>  }
>  
> -static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
> +static bool vtd_decide_config(IntelIOMMUState *s, PCMachineState *pcms,
> +                              Error **errp)
>  {
>      X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
> +    PCMachineClass *pcmc = PC_MACHINE_CLASS(MACHINE_GET_CLASS(pcms));
It's a bit backwards, for devices we usually add a property to affected device
and use compat macros to do the job. As example look at
commit 048a2e8869cb7e26013e40d860c9ebdf8e28c2ac
    x86: ioapic: boost default version to 0x20


>  
>      /* Currently Intel IOMMU IR only support "kernel-irqchip={off|split}" */
>      if (x86_iommu->intr_supported && kvm_irqchip_in_kernel() &&
> @@ -2473,11 +2475,11 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
>      }
>  
>      if (s->intr_eim == ON_OFF_AUTO_AUTO) {
> -        s->intr_eim = x86_iommu->intr_supported && kvm_irqchip_in_kernel() ?
> +        s->intr_eim = (kvm_irqchip_in_kernel() || pcmc->buggy_intel_iommu_eim)
> +                      && x86_iommu->intr_supported ?
>                                                ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
>      }
> -
> -    if (s->intr_eim == ON_OFF_AUTO_ON) {
> +    if (s->intr_eim == ON_OFF_AUTO_ON && !pcmc->buggy_intel_iommu_eim) {
>          if (kvm_irqchip_in_kernel() && !kvm_enable_x2apic()) {
>              error_setg(errp, "eim=on requires support on the KVM side"
>                               "(X2APIC_API, first shipped in v4.7)");
> @@ -2502,7 +2504,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
>      VTD_DPRINTF(GENERAL, "");
>      x86_iommu->type = TYPE_INTEL;
>  
> -    if (!vtd_decide_config(s, errp)) {
> +    if (!vtd_decide_config(s, pcms, errp)) {
>          return;
>      }
>  
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 0b214f24c977..97f419fbf4dd 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -304,8 +304,10 @@ DEFINE_Q35_MACHINE(v2_8, "pc-q35-2.8", NULL,
>  
>  static void pc_q35_2_7_machine_options(MachineClass *m)
>  {
> +    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
>      pc_q35_2_8_machine_options(m);
>      m->alias = NULL;
> +    pcmc->buggy_intel_iommu_eim = true;
>      SET_MACHINE_COMPAT(m, PC_COMPAT_2_7);
>  }
>  
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 47bdf10cfd9b..4bd435f8fa5c 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -143,6 +143,8 @@ struct PCMachineClass {
>      bool save_tsc_khz;
>      /* generate legacy CPU hotplug AML */
>      bool legacy_cpu_hotplug;
> +    /* enable buggy Intel-IOMMU EIM by default */
> +    bool buggy_intel_iommu_eim;
>  };
>  
>  #define TYPE_PC_MACHINE "generic-pc-machine"
Radim Krčmář Oct. 4, 2016, 1:48 p.m. UTC | #2
2016-10-04 14:18+0200, Igor Mammedov:
> On Fri, 30 Sep 2016 18:10:12 +0200
> Radim Krčmář <rkrcmar@redhat.com> wrote:
>> QEMU 2.7 allowed EIM even in configurations that were forbidden in the
>> last patch because they were not working, like old KVM or userspace
>> APIC.  In order to keep backward compatibility, we again allow guests to
>> misbehave in non-obvious ways, and make it the default.
>> 
>> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
>> ---
>> v3: shorten the code [Peter]
>> ---
>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>> @@ -2456,9 +2456,11 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>> -static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
>> +static bool vtd_decide_config(IntelIOMMUState *s, PCMachineState *pcms,
>> +                              Error **errp)
>>  {
>>      X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
>> +    PCMachineClass *pcmc = PC_MACHINE_CLASS(MACHINE_GET_CLASS(pcms));
> It's a bit backwards, for devices we usually add a property to affected device
> and use compat macros to do the job. As example look at
> commit 048a2e8869cb7e26013e40d860c9ebdf8e28c2ac
>     x86: ioapic: boost default version to 0x20

I see, v4 will have a property.  Thanks.
diff mbox

Patch

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index efb018b85544..13a2ac5a8fb9 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -2456,9 +2456,11 @@  static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
     return &vtd_as->as;
 }
 
-static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
+static bool vtd_decide_config(IntelIOMMUState *s, PCMachineState *pcms,
+                              Error **errp)
 {
     X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(MACHINE_GET_CLASS(pcms));
 
     /* Currently Intel IOMMU IR only support "kernel-irqchip={off|split}" */
     if (x86_iommu->intr_supported && kvm_irqchip_in_kernel() &&
@@ -2473,11 +2475,11 @@  static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
     }
 
     if (s->intr_eim == ON_OFF_AUTO_AUTO) {
-        s->intr_eim = x86_iommu->intr_supported && kvm_irqchip_in_kernel() ?
+        s->intr_eim = (kvm_irqchip_in_kernel() || pcmc->buggy_intel_iommu_eim)
+                      && x86_iommu->intr_supported ?
                                               ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
     }
-
-    if (s->intr_eim == ON_OFF_AUTO_ON) {
+    if (s->intr_eim == ON_OFF_AUTO_ON && !pcmc->buggy_intel_iommu_eim) {
         if (kvm_irqchip_in_kernel() && !kvm_enable_x2apic()) {
             error_setg(errp, "eim=on requires support on the KVM side"
                              "(X2APIC_API, first shipped in v4.7)");
@@ -2502,7 +2504,7 @@  static void vtd_realize(DeviceState *dev, Error **errp)
     VTD_DPRINTF(GENERAL, "");
     x86_iommu->type = TYPE_INTEL;
 
-    if (!vtd_decide_config(s, errp)) {
+    if (!vtd_decide_config(s, pcms, errp)) {
         return;
     }
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 0b214f24c977..97f419fbf4dd 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -304,8 +304,10 @@  DEFINE_Q35_MACHINE(v2_8, "pc-q35-2.8", NULL,
 
 static void pc_q35_2_7_machine_options(MachineClass *m)
 {
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pc_q35_2_8_machine_options(m);
     m->alias = NULL;
+    pcmc->buggy_intel_iommu_eim = true;
     SET_MACHINE_COMPAT(m, PC_COMPAT_2_7);
 }
 
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 47bdf10cfd9b..4bd435f8fa5c 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -143,6 +143,8 @@  struct PCMachineClass {
     bool save_tsc_khz;
     /* generate legacy CPU hotplug AML */
     bool legacy_cpu_hotplug;
+    /* enable buggy Intel-IOMMU EIM by default */
+    bool buggy_intel_iommu_eim;
 };
 
 #define TYPE_PC_MACHINE "generic-pc-machine"