From: Feng Wu <feng.wu@intel.com>
To: xen-devel@lists.xen.org
Cc: kevin.tian@intel.com, keir@xen.org, george.dunlap@eu.citrix.com,
andrew.cooper3@citrix.com, dario.faggioli@citrix.com,
jbeulich@suse.com, Feng Wu <feng.wu@intel.com>
Subject: [PATCH v2 3/4] VMX: Assign the right value to 'NDST' field in a concern case
Date: Thu, 26 May 2016 21:39:13 +0800 [thread overview]
Message-ID: <1464269954-8056-4-git-send-email-feng.wu@intel.com> (raw)
In-Reply-To: <1464269954-8056-1-git-send-email-feng.wu@intel.com>
Normally, in vmx_cpu_block() 'NDST' filed should have the same
value with 'dest' or 'MASK_INSR(dest, PI_xAPIC_NDST_MASK)' depending
on whether x2apic is enabled. However, in the following scenario,
'NDST' has different value:
'vcpu_block' hook gets assigned in vmx_pi_hooks_assign(), but all
other three PI hooks have not been assigned or not been excuted yet.
And during this interval, we are running in vmx_vcpu_block(), then
'NDST' may have different value.
This patch fix this concern case.
Signed-off-by: Feng Wu <feng.wu@intel.com>
---
xen/arch/x86/hvm/vmx/vmx.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index b01128a..662b38d 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -146,8 +146,19 @@ static void vmx_vcpu_block(struct vcpu *v)
dest = cpu_physical_id(v->processor);
- ASSERT(pi_desc->ndst ==
- (x2apic_enabled ? dest : MASK_INSR(dest, PI_xAPIC_NDST_MASK)));
+ /*
+ * Normally, 'NDST' filed should have the same value with dest or
+ * MASK_INSR(dest, PI_xAPIC_NDST_MASK) depending on whether x2apic is
+ * enabled. However, in the following scenario, 'NDST' has different
+ * value:
+ *
+ * 'vcpu_block' hook gets assigned in vmx_pi_hooks_assign(), but all
+ * other three PI hooks have not been assigned or not been excuted yet.
+ * And during this interval, we get here in this function, then 'NDST'
+ * may have different value.
+ */
+ write_atomic(&pi_desc->ndst,
+ x2apic_enabled ? dest : MASK_INSR(dest, PI_xAPIC_NDST_MASK));
write_atomic(&pi_desc->nv, pi_wakeup_vector);
}
--
2.1.0
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next prev parent reply other threads:[~2016-05-26 13:39 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-26 13:39 [PATCH v2 0/4] VMX: Properly handle pi descriptor and per-cpu blocking list Feng Wu
2016-05-26 13:39 ` [PATCH v2 1/4] VMX: Properly handle pi when all the assigned devices are removed Feng Wu
2016-05-27 13:43 ` Jan Beulich
2016-05-31 10:22 ` Wu, Feng
2016-05-31 11:52 ` Jan Beulich
2016-06-03 5:12 ` Wu, Feng
2016-06-03 9:45 ` Jan Beulich
2016-05-26 13:39 ` [PATCH v2 2/4] VMX: Cleanup PI per-cpu blocking list when vcpu is destroyed Feng Wu
2016-05-27 13:49 ` Jan Beulich
2016-05-31 10:22 ` Wu, Feng
2016-05-31 11:54 ` Jan Beulich
2016-05-26 13:39 ` Feng Wu [this message]
2016-05-27 14:00 ` [PATCH v2 3/4] VMX: Assign the right value to 'NDST' field in a concern case Jan Beulich
2016-05-31 10:27 ` Wu, Feng
2016-05-31 11:58 ` Jan Beulich
2016-06-03 5:23 ` Wu, Feng
2016-06-03 9:57 ` Jan Beulich
2016-06-22 18:00 ` George Dunlap
2016-06-24 9:08 ` Wu, Feng
2016-05-26 13:39 ` [PATCH v2 4/4] VMX: fixup PI descritpor when cpu is offline Feng Wu
2016-05-27 14:56 ` Jan Beulich
2016-05-31 10:31 ` Wu, Feng
2016-06-22 18:33 ` George Dunlap
2016-06-24 6:34 ` Wu, Feng
2016-05-26 17:20 ` [PATCH v2 0/4] VMX: Properly handle pi descriptor and per-cpu blocking list Dario Faggioli
2016-05-31 10:19 ` Wu, Feng
2016-06-22 21:33 ` Dario Faggioli
2016-06-24 6:33 ` Wu, Feng
2016-06-24 10:29 ` Dario Faggioli
2016-06-24 13:42 ` Wu, Feng
2016-06-24 13:49 ` George Dunlap
2016-06-24 14:36 ` Dario Faggioli
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