* [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler
@ 2016-05-21 23:42 suravee.suthikulpanit
2016-05-21 23:42 ` [PATCH v3 1/3] x86/hvm: Add check when register " suravee.suthikulpanit
` (3 more replies)
0 siblings, 4 replies; 19+ messages in thread
From: suravee.suthikulpanit @ 2016-05-21 23:42 UTC (permalink / raw)
To: xen-devel, paul.durrant, jbeulich, george.dunlap
Cc: keir, Suravee Suthikulpanit
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Hi All,
Changes from V2:
* Use assert instead of sanity check before count increment in
the hvm_next_io_handler().
* Post-pone iommu_domain_init() and add proper error handling code
to destroy hvm in case of failure.
* Split out sanity check in guest_iommu_init() into a separate patch.
OVERVIEW:
On systems with iommu v2 enabled, the hypervisor crashes when trying
to start up an HVM guest.
Investigating shows that the guest_iommu_init() is called before the
HVM domain is initialized. It then tries to register_mmio_handler()
causing the hvm_next_io_handler() to increment the io_handler_count.
However, the registration fails silently and left the I/O handler
uninitialized.
At later time, hvm_find_io_handler() is called and iterate through
the registered handlered, but then resulting in referencing NULL
pointers.
This patch series proposes fix for this issue.
Thanks,
Suravee
Suravee Suthikulpanit (3):
x86/hvm: Add check when register io handler
svm: iommu: Only call guest_iommu_init() after initialized HVM domain
AMD IOMMU: Check io_handler before registering mmio handler
xen/arch/x86/domain.c | 9 ++++++---
xen/arch/x86/hvm/intercept.c | 2 ++
xen/drivers/passthrough/amd/iommu_guest.c | 6 ++++++
3 files changed, 14 insertions(+), 3 deletions(-)
--
1.9.1
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^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH v3 1/3] x86/hvm: Add check when register io handler
2016-05-21 23:42 [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler suravee.suthikulpanit
@ 2016-05-21 23:42 ` suravee.suthikulpanit
2016-05-23 8:17 ` Paul Durrant
2016-05-23 11:46 ` Jan Beulich
2016-05-21 23:42 ` [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain suravee.suthikulpanit
` (2 subsequent siblings)
3 siblings, 2 replies; 19+ messages in thread
From: suravee.suthikulpanit @ 2016-05-21 23:42 UTC (permalink / raw)
To: xen-devel, paul.durrant, jbeulich, george.dunlap
Cc: keir, Suravee Suthikulpanit
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
At the time of registering HVM I/O handler, the HVM domain might
not have been initialized, which means the hvm_domain.io_handler
would be NULL. In the hvm_next_io_handler(), this should be asserted.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
xen/arch/x86/hvm/intercept.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/xen/arch/x86/hvm/intercept.c b/xen/arch/x86/hvm/intercept.c
index fc757d0..2f8d57f 100644
--- a/xen/arch/x86/hvm/intercept.c
+++ b/xen/arch/x86/hvm/intercept.c
@@ -258,6 +258,8 @@ struct hvm_io_handler *hvm_next_io_handler(struct domain *d)
{
unsigned int i = d->arch.hvm_domain.io_handler_count++;
+ ASSERT( d->arch.hvm_domain.io_handler );
+
if ( i == NR_IO_HANDLERS )
{
domain_crash(d);
--
1.9.1
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^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-21 23:42 [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler suravee.suthikulpanit
2016-05-21 23:42 ` [PATCH v3 1/3] x86/hvm: Add check when register " suravee.suthikulpanit
@ 2016-05-21 23:42 ` suravee.suthikulpanit
2016-05-23 8:21 ` Paul Durrant
2016-05-23 11:54 ` Jan Beulich
2016-05-21 23:42 ` [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler suravee.suthikulpanit
2016-05-21 23:47 ` [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler Suravee Suthikulpanit
3 siblings, 2 replies; 19+ messages in thread
From: suravee.suthikulpanit @ 2016-05-21 23:42 UTC (permalink / raw)
To: xen-devel, paul.durrant, jbeulich, george.dunlap
Cc: keir, Suravee Suthikulpanit
From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
The guest_iommu_init() is currently called by the following code path:
arch/x86/domain.c: arch_domain_create()
]- drivers/passthrough/iommu.c: iommu_domain_init()
|- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
|- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
At this point, the hvm_domain_initialised() has not been called.
So register_mmio_handler() in guest_iommu_init() silently fails.
This patch moves the iommu_domain_init() to a later point after the
hvm_domain_intialise() instead.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
xen/arch/x86/domain.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 5af2cc5..0260e01 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -642,9 +642,6 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
if ( (rc = init_domain_irq_mapping(d)) != 0 )
goto fail;
-
- if ( (rc = iommu_domain_init(d)) != 0 )
- goto fail;
}
spin_lock_init(&d->arch.e820_lock);
@@ -660,6 +657,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
/* 64-bit PV guest by default. */
d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 0;
+ if ( !is_idle_domain(d) && (rc = iommu_domain_init(d)) != 0 )
+ goto fail_1;
+
/* initialize default tsc behavior in case tools don't */
tsc_set_info(d, TSC_MODE_DEFAULT, 0UL, 0, 0);
spin_lock_init(&d->arch.vtsc_lock);
@@ -675,6 +675,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
return 0;
+ fail_1:
+ if ( has_hvm_container_domain(d) )
+ hvm_domain_destroy(d);
fail:
d->is_dying = DOMDYING_dead;
psr_domain_free(d);
--
1.9.1
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http://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler
2016-05-21 23:42 [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler suravee.suthikulpanit
2016-05-21 23:42 ` [PATCH v3 1/3] x86/hvm: Add check when register " suravee.suthikulpanit
2016-05-21 23:42 ` [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain suravee.suthikulpanit
@ 2016-05-21 23:42 ` suravee.suthikulpanit
2016-05-23 8:23 ` Paul Durrant
2016-05-21 23:47 ` [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler Suravee Suthikulpanit
3 siblings, 1 reply; 19+ messages in thread
From: suravee.suthikulpanit @ 2016-05-21 23:42 UTC (permalink / raw)
To: xen-devel, paul.durrant, jbeulich, george.dunlap
Cc: keir, Suravee Suthikulapanit
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
guest_iommu_init tries to register mmio handler before HVM domain
is initialized. This cause registration to silently failing.
This patch adds a sanitiy check and puts out error message.
Signed-off-by: Suravee Suthikulapanit <suravee.suthikulpanit@amd.com>
---
xen/drivers/passthrough/amd/iommu_guest.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/xen/drivers/passthrough/amd/iommu_guest.c b/xen/drivers/passthrough/amd/iommu_guest.c
index f96fbf4..49f00de 100644
--- a/xen/drivers/passthrough/amd/iommu_guest.c
+++ b/xen/drivers/passthrough/amd/iommu_guest.c
@@ -890,6 +890,12 @@ int guest_iommu_init(struct domain* d)
!has_viommu(d) )
return 0;
+ if ( d->arch.hvm_domain.io_handler == NULL )
+ {
+ AMD_IOMMU_DEBUG("Error: uninitalized hvm io handler\n");
+ return 1;
+ }
+
iommu = xzalloc(struct guest_iommu);
if ( !iommu )
{
--
1.9.1
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^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler
2016-05-21 23:42 [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler suravee.suthikulpanit
` (2 preceding siblings ...)
2016-05-21 23:42 ` [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler suravee.suthikulpanit
@ 2016-05-21 23:47 ` Suravee Suthikulpanit
3 siblings, 0 replies; 19+ messages in thread
From: Suravee Suthikulpanit @ 2016-05-21 23:47 UTC (permalink / raw)
To: xen-devel, paul.durrant, jbeulich, george.dunlap; +Cc: ruediger.otte, keir
+ Rüdiger
This patch series should help fixing the issue you are seeing.
Thanks,
Suravee
On 05/21/2016 06:42 PM, suravee.suthikulpanit@amd.com wrote:
> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>
> Hi All,
>
> Changes from V2:
> * Use assert instead of sanity check before count increment in
> the hvm_next_io_handler().
> * Post-pone iommu_domain_init() and add proper error handling code
> to destroy hvm in case of failure.
> * Split out sanity check in guest_iommu_init() into a separate patch.
>
> OVERVIEW:
>
> On systems with iommu v2 enabled, the hypervisor crashes when trying
> to start up an HVM guest.
>
> Investigating shows that the guest_iommu_init() is called before the
> HVM domain is initialized. It then tries to register_mmio_handler()
> causing the hvm_next_io_handler() to increment the io_handler_count.
> However, the registration fails silently and left the I/O handler
> uninitialized.
>
> At later time, hvm_find_io_handler() is called and iterate through
> the registered handlered, but then resulting in referencing NULL
> pointers.
>
> This patch series proposes fix for this issue.
>
> Thanks,
> Suravee
>
> Suravee Suthikulpanit (3):
> x86/hvm: Add check when register io handler
> svm: iommu: Only call guest_iommu_init() after initialized HVM domain
> AMD IOMMU: Check io_handler before registering mmio handler
>
> xen/arch/x86/domain.c | 9 ++++++---
> xen/arch/x86/hvm/intercept.c | 2 ++
> xen/drivers/passthrough/amd/iommu_guest.c | 6 ++++++
> 3 files changed, 14 insertions(+), 3 deletions(-)
>
_______________________________________________
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 1/3] x86/hvm: Add check when register io handler
2016-05-21 23:42 ` [PATCH v3 1/3] x86/hvm: Add check when register " suravee.suthikulpanit
@ 2016-05-23 8:17 ` Paul Durrant
2016-05-23 11:46 ` Jan Beulich
1 sibling, 0 replies; 19+ messages in thread
From: Paul Durrant @ 2016-05-23 8:17 UTC (permalink / raw)
To: suravee.suthikulpanit, xen-devel, jbeulich, George Dunlap; +Cc: Keir (Xen.org)
> -----Original Message-----
> From: suravee.suthikulpanit@amd.com
> [mailto:suravee.suthikulpanit@amd.com]
> Sent: 22 May 2016 00:42
> To: xen-devel@lists.xen.org; Paul Durrant; jbeulich@suse.com; George
> Dunlap
> Cc: Keir (Xen.org); Suravee Suthikulpanit; Suravee Suthikulpanit
> Subject: [PATCH v3 1/3] x86/hvm: Add check when register io handler
>
> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>
> At the time of registering HVM I/O handler, the HVM domain might
> not have been initialized, which means the hvm_domain.io_handler
> would be NULL. In the hvm_next_io_handler(), this should be asserted.
>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> ---
> xen/arch/x86/hvm/intercept.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/xen/arch/x86/hvm/intercept.c b/xen/arch/x86/hvm/intercept.c
> index fc757d0..2f8d57f 100644
> --- a/xen/arch/x86/hvm/intercept.c
> +++ b/xen/arch/x86/hvm/intercept.c
> @@ -258,6 +258,8 @@ struct hvm_io_handler *hvm_next_io_handler(struct
> domain *d)
> {
> unsigned int i = d->arch.hvm_domain.io_handler_count++;
>
> + ASSERT( d->arch.hvm_domain.io_handler );
Needs fixing for style, but with that...
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
> +
> if ( i == NR_IO_HANDLERS )
> {
> domain_crash(d);
> --
> 1.9.1
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-21 23:42 ` [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain suravee.suthikulpanit
@ 2016-05-23 8:21 ` Paul Durrant
2016-05-23 11:54 ` Jan Beulich
1 sibling, 0 replies; 19+ messages in thread
From: Paul Durrant @ 2016-05-23 8:21 UTC (permalink / raw)
To: suravee.suthikulpanit, xen-devel, jbeulich, George Dunlap; +Cc: Keir (Xen.org)
> -----Original Message-----
> From: suravee.suthikulpanit@amd.com
> [mailto:suravee.suthikulpanit@amd.com]
> Sent: 22 May 2016 00:43
> To: xen-devel@lists.xen.org; Paul Durrant; jbeulich@suse.com; George
> Dunlap
> Cc: Keir (Xen.org); Suravee Suthikulpanit
> Subject: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after
> initialized HVM domain
>
> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>
> The guest_iommu_init() is currently called by the following code path:
>
> arch/x86/domain.c: arch_domain_create()
> ]- drivers/passthrough/iommu.c: iommu_domain_init()
> |- drivers/passthrough/amd/pci_amd_iommu.c:
> amd_iommu_domain_init();
> |- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
>
> At this point, the hvm_domain_initialised() has not been called.
> So register_mmio_handler() in guest_iommu_init() silently fails.
> This patch moves the iommu_domain_init() to a later point after the
> hvm_domain_intialise() instead.
>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
> ---
> xen/arch/x86/domain.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 5af2cc5..0260e01 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -642,9 +642,6 @@ int arch_domain_create(struct domain *d, unsigned
> int domcr_flags,
>
> if ( (rc = init_domain_irq_mapping(d)) != 0 )
> goto fail;
> -
> - if ( (rc = iommu_domain_init(d)) != 0 )
> - goto fail;
> }
> spin_lock_init(&d->arch.e820_lock);
>
> @@ -660,6 +657,9 @@ int arch_domain_create(struct domain *d, unsigned
> int domcr_flags,
> /* 64-bit PV guest by default. */
> d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 0;
>
> + if ( !is_idle_domain(d) && (rc = iommu_domain_init(d)) != 0 )
> + goto fail_1;
> +
> /* initialize default tsc behavior in case tools don't */
> tsc_set_info(d, TSC_MODE_DEFAULT, 0UL, 0, 0);
> spin_lock_init(&d->arch.vtsc_lock);
> @@ -675,6 +675,9 @@ int arch_domain_create(struct domain *d, unsigned
> int domcr_flags,
>
> return 0;
>
> + fail_1:
> + if ( has_hvm_container_domain(d) )
> + hvm_domain_destroy(d);
> fail:
> d->is_dying = DOMDYING_dead;
> psr_domain_free(d);
> --
> 1.9.1
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler
2016-05-21 23:42 ` [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler suravee.suthikulpanit
@ 2016-05-23 8:23 ` Paul Durrant
2016-05-25 18:52 ` Suravee Suthikulanit
0 siblings, 1 reply; 19+ messages in thread
From: Paul Durrant @ 2016-05-23 8:23 UTC (permalink / raw)
To: suravee.suthikulpanit, xen-devel, jbeulich, George Dunlap; +Cc: Keir (Xen.org)
> -----Original Message-----
> From: suravee.suthikulpanit@amd.com
> [mailto:suravee.suthikulpanit@amd.com]
> Sent: 22 May 2016 00:43
> To: xen-devel@lists.xen.org; Paul Durrant; jbeulich@suse.com; George
> Dunlap
> Cc: Keir (Xen.org); Suravee Suthikulpanit; Suravee Suthikulapanit
> Subject: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering
> mmio handler
>
> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>
> guest_iommu_init tries to register mmio handler before HVM domain
> is initialized. This cause registration to silently failing.
> This patch adds a sanitiy check and puts out error message.
>
> Signed-off-by: Suravee Suthikulapanit <suravee.suthikulpanit@amd.com>
This patch is now defunct isn't it?
Paul
> ---
> xen/drivers/passthrough/amd/iommu_guest.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/xen/drivers/passthrough/amd/iommu_guest.c
> b/xen/drivers/passthrough/amd/iommu_guest.c
> index f96fbf4..49f00de 100644
> --- a/xen/drivers/passthrough/amd/iommu_guest.c
> +++ b/xen/drivers/passthrough/amd/iommu_guest.c
> @@ -890,6 +890,12 @@ int guest_iommu_init(struct domain* d)
> !has_viommu(d) )
> return 0;
>
> + if ( d->arch.hvm_domain.io_handler == NULL )
> + {
> + AMD_IOMMU_DEBUG("Error: uninitalized hvm io handler\n");
> + return 1;
> + }
> +
> iommu = xzalloc(struct guest_iommu);
> if ( !iommu )
> {
> --
> 1.9.1
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 1/3] x86/hvm: Add check when register io handler
2016-05-21 23:42 ` [PATCH v3 1/3] x86/hvm: Add check when register " suravee.suthikulpanit
2016-05-23 8:17 ` Paul Durrant
@ 2016-05-23 11:46 ` Jan Beulich
2016-05-25 19:04 ` Suravee Suthikulanit
1 sibling, 1 reply; 19+ messages in thread
From: Jan Beulich @ 2016-05-23 11:46 UTC (permalink / raw)
To: suravee.suthikulpanit; +Cc: paul.durrant, keir, george.dunlap, xen-devel
>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
> --- a/xen/arch/x86/hvm/intercept.c
> +++ b/xen/arch/x86/hvm/intercept.c
> @@ -258,6 +258,8 @@ struct hvm_io_handler *hvm_next_io_handler(struct domain *d)
> {
> unsigned int i = d->arch.hvm_domain.io_handler_count++;
>
> + ASSERT( d->arch.hvm_domain.io_handler );
Am I wrong in understanding that without patch 2 this ASSERT() will
actually trigger? In which case the patch order would be wrong (but
that could be taken care of during commit).
Jan
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-21 23:42 ` [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain suravee.suthikulpanit
2016-05-23 8:21 ` Paul Durrant
@ 2016-05-23 11:54 ` Jan Beulich
2016-05-25 19:00 ` Suravee Suthikulanit
1 sibling, 1 reply; 19+ messages in thread
From: Jan Beulich @ 2016-05-23 11:54 UTC (permalink / raw)
To: suravee.suthikulpanit; +Cc: paul.durrant, keir, george.dunlap, xen-devel
>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>
> The guest_iommu_init() is currently called by the following code path:
>
> arch/x86/domain.c: arch_domain_create()
> ]- drivers/passthrough/iommu.c: iommu_domain_init()
> |- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
> |- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
>
> At this point, the hvm_domain_initialised() has not been called.
> So register_mmio_handler() in guest_iommu_init() silently fails.
> This patch moves the iommu_domain_init() to a later point after the
> hvm_domain_intialise() instead.
That's one possible approach, which I continue to be not really
happy with. guest_iommu_init() really is HVM-specific, so maybe
no longer calling it from amd_iommu_domain_init() would be the
better solution (instead calling it from hvm_domain_initialise()
would then seem to be the better option). Thoughts?
In any event is the choice of ...
> @@ -675,6 +675,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
>
> return 0;
>
> + fail_1:
> + if ( has_hvm_container_domain(d) )
> + hvm_domain_destroy(d);
> fail:
> d->is_dying = DOMDYING_dead;
> psr_domain_free(d);
... the new label name sub-optimal. Please pick something more
descriptive, e.g. "iommu_fail", if the current approach is to be
retained.
Jan
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler
2016-05-23 8:23 ` Paul Durrant
@ 2016-05-25 18:52 ` Suravee Suthikulanit
2016-05-26 8:28 ` Paul Durrant
2016-05-26 15:47 ` Jan Beulich
0 siblings, 2 replies; 19+ messages in thread
From: Suravee Suthikulanit @ 2016-05-25 18:52 UTC (permalink / raw)
To: Paul Durrant, xen-devel, jbeulich, George Dunlap; +Cc: Keir (Xen.org)
On 5/23/2016 3:23 AM, Paul Durrant wrote:
>> -----Original Message-----
>> > From: suravee.suthikulpanit@amd.com
>> > [mailto:suravee.suthikulpanit@amd.com]
>> > Sent: 22 May 2016 00:43
>> > To: xen-devel@lists.xen.org; Paul Durrant; jbeulich@suse.com; George
>> > Dunlap
>> > Cc: Keir (Xen.org); Suravee Suthikulpanit; Suravee Suthikulapanit
>> > Subject: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering
>> > mmio handler
>> >
>> > From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>> >
>> > guest_iommu_init tries to register mmio handler before HVM domain
>> > is initialized. This cause registration to silently failing.
>> > This patch adds a sanitiy check and puts out error message.
>> >
>> > Signed-off-by: Suravee Suthikulapanit <suravee.suthikulpanit@amd.com>
> This patch is now defunct isn't it?
>
> Paul
>
It is no longer required, but I think this is a good sanity check in
case something changes in the future and causing this to be called
before the HVM I/O handler initialized.
Thanks,
Suravee
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-23 11:54 ` Jan Beulich
@ 2016-05-25 19:00 ` Suravee Suthikulanit
2016-05-26 15:44 ` Jan Beulich
0 siblings, 1 reply; 19+ messages in thread
From: Suravee Suthikulanit @ 2016-05-25 19:00 UTC (permalink / raw)
To: Jan Beulich; +Cc: paul.durrant, keir, george.dunlap, xen-devel
On 5/23/2016 6:54 AM, Jan Beulich wrote:
>>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
>> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>>
>> The guest_iommu_init() is currently called by the following code path:
>>
>> arch/x86/domain.c: arch_domain_create()
>> ]- drivers/passthrough/iommu.c: iommu_domain_init()
>> |- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
>> |- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
>>
>> At this point, the hvm_domain_initialised() has not been called.
>> So register_mmio_handler() in guest_iommu_init() silently fails.
>> This patch moves the iommu_domain_init() to a later point after the
>> hvm_domain_intialise() instead.
>
> That's one possible approach, which I continue to be not really
> happy with. guest_iommu_init() really is HVM-specific, so maybe
> no longer calling it from amd_iommu_domain_init() would be the
> better solution (instead calling it from hvm_domain_initialise()
> would then seem to be the better option). Thoughts?
Then, this goes back to the approach I proposed in the v1 of this patch
series, where I call guest_iommu_init/destroy() in the
svm_domain_initialise/destroy().
However, I'm still not quite clear in why the iommu_domain_init() is
needed before hvm_domain_initialise().
>
> In any event is the choice of ...
>
>> @@ -675,6 +675,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
>>
>> return 0;
>>
>> + fail_1:
>> + if ( has_hvm_container_domain(d) )
>> + hvm_domain_destroy(d);
>> fail:
>> d->is_dying = DOMDYING_dead;
>> psr_domain_free(d);
>
> ... the new label name sub-optimal. Please pick something more
> descriptive, e.g. "iommu_fail", if the current approach is to be
> retained.
>
> Jan
>
In case we are going with this approach, I will make this change.
Thanks,
Suravee
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 1/3] x86/hvm: Add check when register io handler
2016-05-23 11:46 ` Jan Beulich
@ 2016-05-25 19:04 ` Suravee Suthikulanit
0 siblings, 0 replies; 19+ messages in thread
From: Suravee Suthikulanit @ 2016-05-25 19:04 UTC (permalink / raw)
To: Jan Beulich; +Cc: paul.durrant, keir, george.dunlap, xen-devel
On 5/23/2016 6:46 AM, Jan Beulich wrote:
>>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
>> --- a/xen/arch/x86/hvm/intercept.c
>> +++ b/xen/arch/x86/hvm/intercept.c
>> @@ -258,6 +258,8 @@ struct hvm_io_handler *hvm_next_io_handler(struct domain *d)
>> {
>> unsigned int i = d->arch.hvm_domain.io_handler_count++;
>>
>> + ASSERT( d->arch.hvm_domain.io_handler );
>
> Am I wrong in understanding that without patch 2 this ASSERT() will
> actually trigger? In which case the patch order would be wrong (but
> that could be taken care of during commit).
>
> Jan
>
Right, I can fix this in V4 if we decide to change the
iommu_domain_initialise() ordering.
Suravee
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler
2016-05-25 18:52 ` Suravee Suthikulanit
@ 2016-05-26 8:28 ` Paul Durrant
2016-05-26 15:47 ` Jan Beulich
1 sibling, 0 replies; 19+ messages in thread
From: Paul Durrant @ 2016-05-26 8:28 UTC (permalink / raw)
To: Suravee Suthikulanit, xen-devel, jbeulich, George Dunlap; +Cc: Keir (Xen.org)
> -----Original Message-----
> From: Suravee Suthikulanit [mailto:suravee.suthikulpanit@amd.com]
> Sent: 25 May 2016 19:52
> To: Paul Durrant; xen-devel@lists.xen.org; jbeulich@suse.com; George
> Dunlap
> Cc: Keir (Xen.org)
> Subject: Re: [PATCH v3 3/3] AMD IOMMU: Check io_handler before
> registering mmio handler
>
> On 5/23/2016 3:23 AM, Paul Durrant wrote:
> >> -----Original Message-----
> >> > From: suravee.suthikulpanit@amd.com
> >> > [mailto:suravee.suthikulpanit@amd.com]
> >> > Sent: 22 May 2016 00:43
> >> > To: xen-devel@lists.xen.org; Paul Durrant; jbeulich@suse.com; George
> >> > Dunlap
> >> > Cc: Keir (Xen.org); Suravee Suthikulpanit; Suravee Suthikulapanit
> >> > Subject: [PATCH v3 3/3] AMD IOMMU: Check io_handler before
> registering
> >> > mmio handler
> >> >
> >> > From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> >> >
> >> > guest_iommu_init tries to register mmio handler before HVM domain
> >> > is initialized. This cause registration to silently failing.
> >> > This patch adds a sanitiy check and puts out error message.
> >> >
> >> > Signed-off-by: Suravee Suthikulapanit
> <suravee.suthikulpanit@amd.com>
> > This patch is now defunct isn't it?
> >
> > Paul
> >
>
> It is no longer required, but I think this is a good sanity check in
> case something changes in the future and causing this to be called
> before the HVM I/O handler initialized.
Maybe, but shouldn't it result in a domain_crash()?
Paul
>
> Thanks,
> Suravee
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-25 19:00 ` Suravee Suthikulanit
@ 2016-05-26 15:44 ` Jan Beulich
2016-05-31 21:11 ` Suravee Suthikulanit
0 siblings, 1 reply; 19+ messages in thread
From: Jan Beulich @ 2016-05-26 15:44 UTC (permalink / raw)
To: suravee.suthikulpanit; +Cc: paul.durrant, keir, george.dunlap, xen-devel
>>> Suravee Suthikulanit <suravee.suthikulpanit@amd.com> 05/25/16 9:01 PM >>>
>On 5/23/2016 6:54 AM, Jan Beulich wrote:
>>>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
>>> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>>>
>>> The guest_iommu_init() is currently called by the following code path:
>>>
>>> arch/x86/domain.c: arch_domain_create()
>>> ]- drivers/passthrough/iommu.c: iommu_domain_init()
>>> |- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
>>> |- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
>>>
>>> At this point, the hvm_domain_initialised() has not been called.
>>> So register_mmio_handler() in guest_iommu_init() silently fails.
>>> This patch moves the iommu_domain_init() to a later point after the
>>> hvm_domain_intialise() instead.
>>
>> That's one possible approach, which I continue to be not really
>> happy with. guest_iommu_init() really is HVM-specific, so maybe
>> no longer calling it from amd_iommu_domain_init() would be the
>> better solution (instead calling it from hvm_domain_initialise()
>> would then seem to be the better option). Thoughts?
>
>Then, this goes back to the approach I proposed in the v1 of this patch
>series, where I call guest_iommu_init/destroy() in the
>svm_domain_initialise/destroy().
>
>However, I'm still not quite clear in why the iommu_domain_init() is
>needed before hvm_domain_initialise().
I think the two things are only lightly related. Changing the order of calls is
generally fine, but recognizing that guest_iommu_init() really would better be
called elsewhere makes that re-ordering simply unnecessary.
Jan
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler
2016-05-25 18:52 ` Suravee Suthikulanit
2016-05-26 8:28 ` Paul Durrant
@ 2016-05-26 15:47 ` Jan Beulich
1 sibling, 0 replies; 19+ messages in thread
From: Jan Beulich @ 2016-05-26 15:47 UTC (permalink / raw)
To: suravee.suthikulpanit; +Cc: Paul.Durrant, keir, George.Dunlap, xen-devel
>>> Suravee Suthikulanit <suravee.suthikulpanit@amd.com> 05/25/16 8:52 PM >>>
>On 5/23/2016 3:23 AM, Paul Durrant wrote:
>> > From: suravee.suthikulpanit@amd.com
>> > Sent: 22 May 2016 00:43
>>> > guest_iommu_init tries to register mmio handler before HVM domain
>>> > is initialized. This cause registration to silently failing.
>>> > This patch adds a sanitiy check and puts out error message.
>>> >
>>> > Signed-off-by: Suravee Suthikulapanit <suravee.suthikulpanit@amd.com>
>> This patch is now defunct isn't it?
>
>It is no longer required, but I think this is a good sanity check in
>case something changes in the future and causing this to be called
>before the HVM I/O handler initialized.
To be honest, in this case I'm not convinced, no matter that generally
appreciate ASSERT()s getting added.
Jan
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-26 15:44 ` Jan Beulich
@ 2016-05-31 21:11 ` Suravee Suthikulanit
2016-06-01 7:55 ` Jan Beulich
0 siblings, 1 reply; 19+ messages in thread
From: Suravee Suthikulanit @ 2016-05-31 21:11 UTC (permalink / raw)
To: Jan Beulich; +Cc: paul.durrant, keir, george.dunlap, xen-devel
On 5/26/2016 10:44 AM, Jan Beulich wrote:
>>>> Suravee Suthikulanit <suravee.suthikulpanit@amd.com> 05/25/16 9:01 PM >>>
>> On 5/23/2016 6:54 AM, Jan Beulich wrote:
>>>>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
>>>> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>>>>
>>>> The guest_iommu_init() is currently called by the following code path:
>>>>
>>>> arch/x86/domain.c: arch_domain_create()
>>>> ]- drivers/passthrough/iommu.c: iommu_domain_init()
>>>> |- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
>>>> |- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
>>>>
>>>> At this point, the hvm_domain_initialised() has not been called.
>>>> So register_mmio_handler() in guest_iommu_init() silently fails.
>>>> This patch moves the iommu_domain_init() to a later point after the
>>>> hvm_domain_intialise() instead.
>>>
>>> That's one possible approach, which I continue to be not really
>>> happy with. guest_iommu_init() really is HVM-specific, so maybe
>>> no longer calling it from amd_iommu_domain_init() would be the
>>> better solution (instead calling it from hvm_domain_initialise()
>>> would then seem to be the better option). Thoughts?
>>
>> Then, this goes back to the approach I proposed in the v1 of this patch
>> series, where I call guest_iommu_init/destroy() in the
>> svm_domain_initialise/destroy().
>>
>> However, I'm still not quite clear in why the iommu_domain_init() is
>> needed before hvm_domain_initialise().
>
> I think the two things are only lightly related. Changing the order of calls is
> generally fine, but recognizing that guest_iommu_init() really would better be
> called elsewhere makes that re-ordering simply unnecessary.
>
> Jan
So, let discussing these two things separately. I would propose to:
1. Let's just remove the guest_iommu_init() for now since it's not
functioning, and it seems to not being called at a proper place
according to Jan. We will revisit this when we re-introduce and fully
test out the feature.
2. As for the ordering of the iommu_domain_init() and hvm_domain_init()
, let's continue to discuss to find proper ordering if it needs changing.
Let me know what you guys thinks.
Thanks,
Suravee
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^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-31 21:11 ` Suravee Suthikulanit
@ 2016-06-01 7:55 ` Jan Beulich
0 siblings, 0 replies; 19+ messages in thread
From: Jan Beulich @ 2016-06-01 7:55 UTC (permalink / raw)
To: Suravee Suthikulanit; +Cc: paul.durrant, keir, george.dunlap, xen-devel
>>> On 31.05.16 at 23:11, <suravee.suthikulpanit@amd.com> wrote:
> On 5/26/2016 10:44 AM, Jan Beulich wrote:
>>>>> Suravee Suthikulanit <suravee.suthikulpanit@amd.com> 05/25/16 9:01 PM >>>
>>> On 5/23/2016 6:54 AM, Jan Beulich wrote:
>>>>>>> On 22.05.16 at 01:42, <suravee.suthikulpanit@amd.com> wrote:
>>>>> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>>>>>
>>>>> The guest_iommu_init() is currently called by the following code path:
>>>>>
>>>>> arch/x86/domain.c: arch_domain_create()
>>>>> ]- drivers/passthrough/iommu.c: iommu_domain_init()
>>>>> |- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
>>>>> |- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
>>>>>
>>>>> At this point, the hvm_domain_initialised() has not been called.
>>>>> So register_mmio_handler() in guest_iommu_init() silently fails.
>>>>> This patch moves the iommu_domain_init() to a later point after the
>>>>> hvm_domain_intialise() instead.
>>>>
>>>> That's one possible approach, which I continue to be not really
>>>> happy with. guest_iommu_init() really is HVM-specific, so maybe
>>>> no longer calling it from amd_iommu_domain_init() would be the
>>>> better solution (instead calling it from hvm_domain_initialise()
>>>> would then seem to be the better option). Thoughts?
>>>
>>> Then, this goes back to the approach I proposed in the v1 of this patch
>>> series, where I call guest_iommu_init/destroy() in the
>>> svm_domain_initialise/destroy().
>>>
>>> However, I'm still not quite clear in why the iommu_domain_init() is
>>> needed before hvm_domain_initialise().
>>
>> I think the two things are only lightly related. Changing the order of calls
> is
>> generally fine, but recognizing that guest_iommu_init() really would better
> be
>> called elsewhere makes that re-ordering simply unnecessary.
>>
>> Jan
>
> So, let discussing these two things separately. I would propose to:
>
> 1. Let's just remove the guest_iommu_init() for now since it's not
> functioning, and it seems to not being called at a proper place
> according to Jan. We will revisit this when we re-introduce and fully
> test out the feature.
Fine with me.
> 2. As for the ordering of the iommu_domain_init() and hvm_domain_init()
> , let's continue to discuss to find proper ordering if it needs changing.
Sure. The only thing I'd like to avoid is a change for the change's sake.
Jan
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^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain
2016-05-21 23:33 suravee.suthikulpanit
@ 2016-05-21 23:33 ` suravee.suthikulpanit
0 siblings, 0 replies; 19+ messages in thread
From: suravee.suthikulpanit @ 2016-05-21 23:33 UTC (permalink / raw)
To: xen-devel, paul.durrant, jbeulich, george.dunlap
Cc: keir, Suravee Suthikulpanit
From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
The guest_iommu_init() is currently called by the following code path:
arch/x86/domain.c: arch_domain_create()
]- drivers/passthrough/iommu.c: iommu_domain_init()
|- drivers/passthrough/amd/pci_amd_iommu.c: amd_iommu_domain_init();
|- drivers/passthrough/amd/iommu_guest.c: guest_iommu_init()
At this point, the hvm_domain_initialised() has not been called.
So register_mmio_handler() in guest_iommu_init() silently fails.
This patch moves the iommu_domain_init() to a later point after the
hvm_domain_intialise() instead.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
xen/arch/x86/domain.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 5af2cc5..0260e01 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -642,9 +642,6 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
if ( (rc = init_domain_irq_mapping(d)) != 0 )
goto fail;
-
- if ( (rc = iommu_domain_init(d)) != 0 )
- goto fail;
}
spin_lock_init(&d->arch.e820_lock);
@@ -660,6 +657,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
/* 64-bit PV guest by default. */
d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 0;
+ if ( !is_idle_domain(d) && (rc = iommu_domain_init(d)) != 0 )
+ goto fail_1;
+
/* initialize default tsc behavior in case tools don't */
tsc_set_info(d, TSC_MODE_DEFAULT, 0UL, 0, 0);
spin_lock_init(&d->arch.vtsc_lock);
@@ -675,6 +675,9 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
return 0;
+ fail_1:
+ if ( has_hvm_container_domain(d) )
+ hvm_domain_destroy(d);
fail:
d->is_dying = DOMDYING_dead;
psr_domain_free(d);
--
1.9.1
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^ permalink raw reply related [flat|nested] 19+ messages in thread
end of thread, other threads:[~2016-06-01 7:55 UTC | newest]
Thread overview: 19+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-21 23:42 [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler suravee.suthikulpanit
2016-05-21 23:42 ` [PATCH v3 1/3] x86/hvm: Add check when register " suravee.suthikulpanit
2016-05-23 8:17 ` Paul Durrant
2016-05-23 11:46 ` Jan Beulich
2016-05-25 19:04 ` Suravee Suthikulanit
2016-05-21 23:42 ` [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain suravee.suthikulpanit
2016-05-23 8:21 ` Paul Durrant
2016-05-23 11:54 ` Jan Beulich
2016-05-25 19:00 ` Suravee Suthikulanit
2016-05-26 15:44 ` Jan Beulich
2016-05-31 21:11 ` Suravee Suthikulanit
2016-06-01 7:55 ` Jan Beulich
2016-05-21 23:42 ` [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering mmio handler suravee.suthikulpanit
2016-05-23 8:23 ` Paul Durrant
2016-05-25 18:52 ` Suravee Suthikulanit
2016-05-26 8:28 ` Paul Durrant
2016-05-26 15:47 ` Jan Beulich
2016-05-21 23:47 ` [PATCH v3 0/3] Fix xen crash when starting HVM guest due to missing io handler Suravee Suthikulpanit
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2016-05-21 23:33 suravee.suthikulpanit
2016-05-21 23:33 ` [PATCH v3 2/3] svm: iommu: Only call guest_iommu_init() after initialized HVM domain suravee.suthikulpanit
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