* [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI
@ 2017-09-14 20:18 Mohammed Gamal
2017-09-14 20:24 ` Thomas Huth
0 siblings, 1 reply; 6+ messages in thread
From: Mohammed Gamal @ 2017-09-14 20:18 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, ehabkost, mst, thuth, Mohammed Gamal
Starting the following command line causes a segfault
qemu-system-x86_64 -S -machine isapc,accel=kvm -device amd-iommu
This is due to the fact that the machine type 'isapc' doesn't have
a PCI bus, while amd_iommu doesn't check if the machine has PCI support
and subsequently does a null-pointer access. AMD IOMMU shouldn't even work
if the target machine doesn't have PCI.
Add a check for PCI on the given machine type and return an error if PCI
is not supported.
Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
---
hw/i386/amd_iommu.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 334938a..9a667b7 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -1153,6 +1153,13 @@ static void amdvi_realize(DeviceState *dev, Error **err)
}
bus = pcms->bus;
+
+ if (!bus) {
+ error_setg(err, "Machine-type '%s' does not support PCI",
+ mc->name);
+ return;
+ }
+
s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
amdvi_uint64_equal, g_free, g_free);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI
2017-09-14 20:18 [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI Mohammed Gamal
@ 2017-09-14 20:24 ` Thomas Huth
2017-09-14 20:31 ` Eduardo Habkost
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Huth @ 2017-09-14 20:24 UTC (permalink / raw)
To: Mohammed Gamal, qemu-devel; +Cc: pbonzini, ehabkost, mst
On 14.09.2017 22:18, Mohammed Gamal wrote:
> Starting the following command line causes a segfault
> qemu-system-x86_64 -S -machine isapc,accel=kvm -device amd-iommu
>
> This is due to the fact that the machine type 'isapc' doesn't have
> a PCI bus, while amd_iommu doesn't check if the machine has PCI support
> and subsequently does a null-pointer access. AMD IOMMU shouldn't even work
> if the target machine doesn't have PCI.
>
> Add a check for PCI on the given machine type and return an error if PCI
> is not supported.
>
> Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
> ---
> hw/i386/amd_iommu.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> index 334938a..9a667b7 100644
> --- a/hw/i386/amd_iommu.c
> +++ b/hw/i386/amd_iommu.c
> @@ -1153,6 +1153,13 @@ static void amdvi_realize(DeviceState *dev, Error **err)
> }
>
> bus = pcms->bus;
> +
> + if (!bus) {
> + error_setg(err, "Machine-type '%s' does not support PCI",
> + mc->name);
> + return;
> + }
> +
> s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
> amdvi_uint64_equal, g_free, g_free);
>
>
Patch looks fine to me, but I think it would also be sufficient to
change the check at the beginning of the function to test "if (!pcms ||
!pcms->bus)" instead of just "if (!pcms)" ... the error message
"Machine-type 'xxx' not supported by amd-iommu" is also adequate if
there is no PCI bus available on the system.
Thomas
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI
2017-09-14 20:24 ` Thomas Huth
@ 2017-09-14 20:31 ` Eduardo Habkost
2017-09-15 2:07 ` Peter Xu
0 siblings, 1 reply; 6+ messages in thread
From: Eduardo Habkost @ 2017-09-14 20:31 UTC (permalink / raw)
To: Thomas Huth; +Cc: Mohammed Gamal, qemu-devel, pbonzini, mst
On Thu, Sep 14, 2017 at 10:24:23PM +0200, Thomas Huth wrote:
> On 14.09.2017 22:18, Mohammed Gamal wrote:
> > Starting the following command line causes a segfault
> > qemu-system-x86_64 -S -machine isapc,accel=kvm -device amd-iommu
> >
> > This is due to the fact that the machine type 'isapc' doesn't have
> > a PCI bus, while amd_iommu doesn't check if the machine has PCI support
> > and subsequently does a null-pointer access. AMD IOMMU shouldn't even work
> > if the target machine doesn't have PCI.
> >
> > Add a check for PCI on the given machine type and return an error if PCI
> > is not supported.
> >
> > Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
> > ---
> > hw/i386/amd_iommu.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> > index 334938a..9a667b7 100644
> > --- a/hw/i386/amd_iommu.c
> > +++ b/hw/i386/amd_iommu.c
> > @@ -1153,6 +1153,13 @@ static void amdvi_realize(DeviceState *dev, Error **err)
> > }
> >
> > bus = pcms->bus;
> > +
> > + if (!bus) {
> > + error_setg(err, "Machine-type '%s' does not support PCI",
> > + mc->name);
> > + return;
> > + }
> > +
> > s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
> > amdvi_uint64_equal, g_free, g_free);
> >
> >
>
> Patch looks fine to me, but I think it would also be sufficient to
> change the check at the beginning of the function to test "if (!pcms ||
> !pcms->bus)" instead of just "if (!pcms)" ... the error message
> "Machine-type 'xxx' not supported by amd-iommu" is also adequate if
> there is no PCI bus available on the system.
I agree this would be much simpler.
--
Eduardo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI
2017-09-14 20:31 ` Eduardo Habkost
@ 2017-09-15 2:07 ` Peter Xu
2017-09-15 9:59 ` Mohammed Gamal
0 siblings, 1 reply; 6+ messages in thread
From: Peter Xu @ 2017-09-15 2:07 UTC (permalink / raw)
To: Eduardo Habkost; +Cc: Thomas Huth, pbonzini, Mohammed Gamal, qemu-devel, mst
On Thu, Sep 14, 2017 at 05:31:38PM -0300, Eduardo Habkost wrote:
> On Thu, Sep 14, 2017 at 10:24:23PM +0200, Thomas Huth wrote:
> > On 14.09.2017 22:18, Mohammed Gamal wrote:
> > > Starting the following command line causes a segfault
> > > qemu-system-x86_64 -S -machine isapc,accel=kvm -device amd-iommu
> > >
> > > This is due to the fact that the machine type 'isapc' doesn't have
> > > a PCI bus, while amd_iommu doesn't check if the machine has PCI support
> > > and subsequently does a null-pointer access. AMD IOMMU shouldn't even work
> > > if the target machine doesn't have PCI.
> > >
> > > Add a check for PCI on the given machine type and return an error if PCI
> > > is not supported.
> > >
> > > Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
> > > ---
> > > hw/i386/amd_iommu.c | 7 +++++++
> > > 1 file changed, 7 insertions(+)
> > >
> > > diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> > > index 334938a..9a667b7 100644
> > > --- a/hw/i386/amd_iommu.c
> > > +++ b/hw/i386/amd_iommu.c
> > > @@ -1153,6 +1153,13 @@ static void amdvi_realize(DeviceState *dev, Error **err)
> > > }
> > >
> > > bus = pcms->bus;
> > > +
> > > + if (!bus) {
> > > + error_setg(err, "Machine-type '%s' does not support PCI",
> > > + mc->name);
> > > + return;
> > > + }
> > > +
> > > s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
> > > amdvi_uint64_equal, g_free, g_free);
> > >
> > >
> >
> > Patch looks fine to me, but I think it would also be sufficient to
> > change the check at the beginning of the function to test "if (!pcms ||
> > !pcms->bus)" instead of just "if (!pcms)" ... the error message
> > "Machine-type 'xxx' not supported by amd-iommu" is also adequate if
> > there is no PCI bus available on the system.
>
> I agree this would be much simpler.
Even, shall we move the pcms && bus check into x86_iommu_realize()
directly? Then we will only need one single patch for Intel/AMD, and
it's also a cleanup. Thanks,
--
Peter Xu
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI
2017-09-15 2:07 ` Peter Xu
@ 2017-09-15 9:59 ` Mohammed Gamal
0 siblings, 0 replies; 6+ messages in thread
From: Mohammed Gamal @ 2017-09-15 9:59 UTC (permalink / raw)
To: Peter Xu; +Cc: Eduardo Habkost, pbonzini, Thomas Huth, qemu-devel, mst
On Fri, 2017-09-15 at 10:07 +0800, Peter Xu wrote:
> On Thu, Sep 14, 2017 at 05:31:38PM -0300, Eduardo Habkost wrote:
> > On Thu, Sep 14, 2017 at 10:24:23PM +0200, Thomas Huth wrote:
> > > On 14.09.2017 22:18, Mohammed Gamal wrote:
> > > > Starting the following command line causes a segfault
> > > > qemu-system-x86_64 -S -machine isapc,accel=kvm -device amd-iommu
> > > >
> > > > This is due to the fact that the machine type 'isapc' doesn't have
> > > > a PCI bus, while amd_iommu doesn't check if the machine has PCI support
> > > > and subsequently does a null-pointer access. AMD IOMMU shouldn't even work
> > > > if the target machine doesn't have PCI.
> > > >
> > > > Add a check for PCI on the given machine type and return an error if PCI
> > > > is not supported.
> > > >
> > > > Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
> > > > ---
> > > > hw/i386/amd_iommu.c | 7 +++++++
> > > > 1 file changed, 7 insertions(+)
> > > >
> > > > diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> > > > index 334938a..9a667b7 100644
> > > > --- a/hw/i386/amd_iommu.c
> > > > +++ b/hw/i386/amd_iommu.c
> > > > @@ -1153,6 +1153,13 @@ static void amdvi_realize(DeviceState *dev, Error **err)
> > > > }
> > > >
> > > > bus = pcms->bus;
> > > > +
> > > > + if (!bus) {
> > > > + error_setg(err, "Machine-type '%s' does not support PCI",
> > > > + mc->name);
> > > > + return;
> > > > + }
> > > > +
> > > > s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
> > > > amdvi_uint64_equal, g_free, g_free);
> > > >
> > > >
> > >
> > > Patch looks fine to me, but I think it would also be sufficient to
> > > change the check at the beginning of the function to test "if (!pcms ||
> > > !pcms->bus)" instead of just "if (!pcms)" ... the error message
> > > "Machine-type 'xxx' not supported by amd-iommu" is also adequate if
> > > there is no PCI bus available on the system.
> >
> > I agree this would be much simpler.
>
> Even, shall we move the pcms && bus check into x86_iommu_realize()
> directly? Then we will only need one single patch for Intel/AMD, and
> it's also a cleanup. Thanks,
Although it's more straight forward to do the checks in amdvi_realize()
and vtd_realize() at the moment, I think moving the checks to
x86_iommu_realize() would be better on the longer term. I will be
sending out a new patch with this change shortly.
Regards,
Mohammed
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI
@ 2017-09-14 19:50 Mohammed Gamal
0 siblings, 0 replies; 6+ messages in thread
From: Mohammed Gamal @ 2017-09-14 19:50 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, ehabkost, mst, thuth, Mohammed Gamal
Starting the following command line causes a segfault
qemu-system-x86_64 -S -machine isapc,accel=kvm -device amd-iommu
This is due to the fact that the machine type 'isapc' doesn't have
a PCI bus, while amd_iommu doesn't check if the machine has PCI support
and subsequently does a null-pointer access. AMD IOMMU shouldn't even work
if the target machine doesn't have PCI.
Add a check for PCI on the given machine type and return an error if PCI
is not supported.
Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
---
hw/i386/amd_iommu.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 334938a..9a667b7 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -1153,6 +1153,13 @@ static void amdvi_realize(DeviceState *dev, Error **err)
}
bus = pcms->bus;
+
+ if (!bus) {
+ error_setg(err, "Machine-type '%s' does not support PCI",
+ mc->name);
+ return;
+ }
+
s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
amdvi_uint64_equal, g_free, g_free);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-09-15 10:00 UTC | newest]
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2017-09-14 20:18 [Qemu-devel] [PATCH] amd_iommu: Return error on machines with no PCI Mohammed Gamal
2017-09-14 20:24 ` Thomas Huth
2017-09-14 20:31 ` Eduardo Habkost
2017-09-15 2:07 ` Peter Xu
2017-09-15 9:59 ` Mohammed Gamal
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2017-09-14 19:50 Mohammed Gamal
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