From e489eb6138e7efe4214a7e9ba0d21f54fc5b7d35 Mon Sep 17 00:00:00 2001 From: Chao Gao Date: Thu, 10 Aug 2017 12:32:16 +0200 Subject: [PATCH] VT-d PI: disable VT-d PI when CPU-side PI isn't enabled From the context calling pi_desc_init(), we can conclude the current implementation of VT-d PI depends on CPU-side PI. If we enable VT-d PI and disable CPU-side PI by disabling APICv explicitly in xen boot command line, we would get an assertion failure. This patch clears iommu_intpost once finding CPU-side PI won't be enabled. It is safe for this is done before this flag starts taking effect. Also take this chance to remove the useless check of "acknowledge interrupt on exit", which is a minimal requirement which has been checked earlier. Signed-off-by: Chao Gao Reviewed-by: Jan Beulich Acked-by: Kevin Tian --- xen/arch/x86/hvm/vmx/vmcs.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c index 2008fee280..7854802cba 100644 --- a/xen/arch/x86/hvm/vmx/vmcs.c +++ b/xen/arch/x86/hvm/vmx/vmcs.c @@ -345,11 +345,19 @@ static int vmx_init_vmcs_config(void) /* * "Process posted interrupt" can be set only when "virtual-interrupt - * delivery" and "acknowledge interrupt on exit" is set + * delivery" and "acknowledge interrupt on exit" is set. For the latter + * is a minimal requirement, only check the former, which is optional. */ - if ( !(_vmx_secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) - || !(_vmx_vmexit_control & VM_EXIT_ACK_INTR_ON_EXIT) ) - _vmx_pin_based_exec_control &= ~ PIN_BASED_POSTED_INTERRUPT; + if ( !(_vmx_secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) ) + _vmx_pin_based_exec_control &= ~PIN_BASED_POSTED_INTERRUPT; + + if ( iommu_intpost && + !(_vmx_pin_based_exec_control & PIN_BASED_POSTED_INTERRUPT) ) + { + printk("Intel VT-d Posted Interrupt is disabled for CPU-side Posted " + "Interrupt is not enabled\n"); + iommu_intpost = 0; + } /* The IA32_VMX_VMFUNC MSR exists only when VMFUNC is available */ if ( _vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VM_FUNCTIONS ) -- 2.30.2