From: Feng Wu <feng.wu@intel.com>
To: xen-devel@lists.xen.org
Cc: Keir Fraser <keir@xen.org>, Kevin Tian <kevin.tian@intel.com>,
Feng Wu <feng.wu@intel.com>, Jan Beulich <jbeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [v4 14/17] vmx: Properly handle notification event when vCPU is running
Date: Thu, 23 Jul 2015 19:35:50 +0800 [thread overview]
Message-ID: <1437651353-5275-15-git-send-email-feng.wu@intel.com> (raw)
In-Reply-To: <1437651353-5275-1-git-send-email-feng.wu@intel.com>
When a vCPU is running in Root mode and a notification event
has been injected to it. we need to set VCPU_KICK_SOFTIRQ for
the current cpu, so the pending interrupt in PIRR will be
synced to vIRR before VM-Exit in time.
CC: Kevin Tian <kevin.tian@intel.com>
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <jbeulich@suse.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
---
v4:
- Coding style.
v3:
- Make pi_notification_interrupt() static
xen/arch/x86/hvm/vmx/vmx.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 46 insertions(+), 1 deletion(-)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index d137ea0..f2b7fe0 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1907,6 +1907,51 @@ static void pi_wakeup_interrupt(struct cpu_user_regs *regs)
this_cpu(irq_count)++;
}
+/* Handle VT-d posted-interrupt when VCPU is running. */
+static void pi_notification_interrupt(struct cpu_user_regs *regs)
+{
+ /*
+ * We get here when a vCPU is running in root-mode (such as via hypercall,
+ * or any other reasons which can result in VM-Exit), and before vCPU is
+ * back to non-root, external interrupts from an assigned device happen
+ * and a notification event is delivered to this logical CPU.
+ *
+ * we need to set VCPU_KICK_SOFTIRQ for the current cpu, just like
+ * __vmx_deliver_posted_interrupt(). So the pending interrupt in PIRR will
+ * be synced to vIRR before VM-Exit in time.
+ *
+ * Please refer to the following code fragments from
+ * xen/arch/x86/hvm/vmx/entry.S:
+ *
+ * .Lvmx_do_vmentry
+ *
+ * ......
+ * point 1
+ *
+ * cmp %ecx,(%rdx,%rax,1)
+ * jnz .Lvmx_process_softirqs
+ *
+ * ......
+ *
+ * je .Lvmx_launch
+ *
+ * ......
+ *
+ * .Lvmx_process_softirqs:
+ * sti
+ * call do_softirq
+ * jmp .Lvmx_do_vmentry
+ *
+ * If VT-d engine issues a notification event at point 1 above, it cannot
+ * be delivered to the guest during this VM-entry without raising the
+ * softirq in this notification handler.
+ */
+ raise_softirq(VCPU_KICK_SOFTIRQ);
+
+ ack_APIC_irq();
+ this_cpu(irq_count)++;
+}
+
const struct hvm_function_table * __init start_vmx(void)
{
set_in_cr4(X86_CR4_VMXE);
@@ -1944,7 +1989,7 @@ const struct hvm_function_table * __init start_vmx(void)
if ( cpu_has_vmx_posted_intr_processing )
{
- alloc_direct_apic_vector(&posted_intr_vector, event_check_interrupt);
+ alloc_direct_apic_vector(&posted_intr_vector, pi_notification_interrupt);
if ( iommu_intpost )
alloc_direct_apic_vector(&pi_wakeup_vector, pi_wakeup_interrupt);
--
2.1.0
next prev parent reply other threads:[~2015-07-23 11:35 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-23 11:35 [v4 00/17] Add VT-d Posted-Interrupts support Feng Wu
2015-07-23 11:35 ` [v4 01/17] VT-d Posted-intterrupt (PI) design Feng Wu
2015-07-23 11:35 ` [v4 02/17] Add helper macro for X86_FEATURE_CX16 feature detection Feng Wu
2015-07-23 11:35 ` [v4 03/17] Add cmpxchg16b support for x86-64 Feng Wu
2015-07-24 15:03 ` Jan Beulich
2015-07-23 11:35 ` [v4 04/17] iommu: Add iommu_intpost to control VT-d Posted-Interrupts feature Feng Wu
2015-07-23 14:01 ` Andrew Cooper
2015-07-23 14:05 ` Andrew Cooper
2015-07-24 0:47 ` Wu, Feng
2015-07-23 11:35 ` [v4 05/17] vt-d: VT-d Posted-Interrupts feature detection Feng Wu
2015-07-24 15:05 ` Jan Beulich
2015-07-23 11:35 ` [v4 06/17] vmx: Extend struct pi_desc to support VT-d Posted-Interrupts Feng Wu
2015-07-23 11:35 ` [v4 07/17] vmx: Add some helper functions for Posted-Interrupts Feng Wu
2015-07-23 11:35 ` [v4 08/17] vmx: Initialize VT-d Posted-Interrupts Descriptor Feng Wu
2015-07-23 11:35 ` [v4 09/17] vmx: Suppress posting interrupts when 'SN' is set Feng Wu
2015-07-24 15:11 ` Jan Beulich
2015-07-23 11:35 ` [v4 10/17] vt-d: Extend struct iremap_entry to support VT-d Posted-Interrupts Feng Wu
2015-07-24 15:13 ` Jan Beulich
2015-07-23 11:35 ` [v4 11/17] vt-d: Add API to update IRTE when VT-d PI is used Feng Wu
2015-07-23 13:51 ` Andrew Cooper
2015-07-23 15:52 ` Jan Beulich
2015-07-23 15:55 ` Andrew Cooper
2015-07-23 16:00 ` Jan Beulich
2015-07-23 16:11 ` Andrew Cooper
2015-07-24 0:39 ` Wu, Feng
2015-07-24 15:27 ` Jan Beulich
2015-07-28 7:34 ` Wu, Feng
2015-08-11 10:18 ` Jan Beulich
2015-07-23 11:35 ` [v4 12/17] Update IRTE according to guest interrupt config changes Feng Wu
2015-07-23 11:35 ` [v4 13/17] vmx: posted-interrupt handling when vCPU is blocked Feng Wu
2015-07-23 11:35 ` Feng Wu [this message]
2015-07-23 11:35 ` [v4 15/17] arm: add a dummy arch hooks for scheduler Feng Wu
2015-07-23 11:54 ` Julien Grall
2015-07-24 0:39 ` Wu, Feng
2015-07-23 11:58 ` Jan Beulich
2015-07-23 11:35 ` [v4 16/17] vmx: Add some scheduler hooks for VT-d posted interrupts Feng Wu
2015-07-23 12:50 ` Dario Faggioli
2015-07-24 0:49 ` Wu, Feng
2015-07-28 14:15 ` Dario Faggioli
2015-07-30 2:04 ` Wu, Feng
2015-07-30 18:26 ` Dario Faggioli
2015-08-11 10:23 ` Jan Beulich
2015-07-23 11:35 ` [v4 17/17] VT-d: Dump the posted format IRTE Feng Wu
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