Hi,
On 20/10/17 15:16, Jan Beulich wrote:
On 20.10.17 at 15:23, <julien.gr...@linaro.org> wrote:
On 20/10/17 12:42, Jan Beulich wrote:
On 20.10.17 at 02:35, <chao....@intel.com> wrote:
pt_update_irq() is expected to return the vector number of periodic
timer interrupt, which should be set in vIRR of vlapic or in PIR.
Otherwise it would trigger the assertion in vmx_intr_assist(), please
seeing
https://lists.xenproject.org/archives/html/xen-devel/2017-10/msg00915.html.
But it fails to achieve that in the following two case:
1. hvm_isa_irq_assert() may not set the corresponding bit in vIRR for
mask field of IOAPIC RTE is set. Please refer to the call tree
vmx_intr_assist() -> pt_update_irq() -> hvm_isa_irq_assert() ->
assert_irq() -> assert_gsi() -> vioapic_irq_positive_edge(). The patch
checks whether the vector is set or not in vIRR of vlapic or PIR before
returning.
2. someone changes the vector field of IOAPIC RTE between asserting
the irq and getting the vector of the irq, leading to setting the
old vector number but returning a different vector number. This patch
allows hvm_isa_irq_assert() to accept a callback which can get the
interrupt vector with irq_lock held. Thus, no one can change the vector
between the two operations.
BTW, the first argument of pi_test_and_set_pir() should be uint8_t
and I take this chance to fix it.
Signed-off-by: Chao Gao <chao....@intel.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
Do you have any opinion on this patch going to Xen 4.10?
Well, the author having hopes that this addresses the assertion
failure we keep seeing in osstest every once in a while, I think
we certainly want to have it despite me not being fully convinced
that it'll actually help. I'm sufficiently convinced though it won't do
any bad.
I guess it is worth having a try then:
Release-acked-by: Julien Grall <julien.gr...@linaro.org>
Cheers,
--
Julien Grall
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