linux-kernel - [PATCH v4 13/25] KVM: VMX: Check CPU_BASED_{INTR,NMI}_WINDOW_EXITING in setup_vmcs

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Message-Id: <20220714091327.1085353-14-vkuznets@redhat.com>
Date:   Thu, 14 Jul 2022 11:13:15 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>
Cc:     Anirudh Rayabharam <anrayabh@...ux.microsoft.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 13/25] KVM: VMX: Check CPU_BASED_{INTR,NMI}_WINDOW_EXITING in setup_vmcs_config()

CPU_BASED_{INTR,NMI}_WINDOW_EXITING controls are toggled dynamically by
vmx_enable_{irq,nmi}_window, handle_interrupt_window(), handle_nmi_window()
but setup_vmcs_config() doesn't check their existence. Add the check and
filter the controls out in vmx_exec_control().

Note: KVM explicitly supports CPUs without VIRTUAL_NMIS and all these CPUs
are supposedly lacking NMI_WINDOW_EXITING too. Adjust cpu_has_virtual_nmis()
accordingly.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/vmx/capabilities.h | 3 ++-
 arch/x86/kvm/vmx/vmx.c          | 8 +++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 069d8d298e1d..07e7492fe72a 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -82,7 +82,8 @@ static inline bool cpu_has_vmx_basic_inout(void)
 
 static inline bool cpu_has_virtual_nmis(void)
 {
-	return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS;
+	return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS &&
+		vmcs_config.cpu_based_exec_ctrl & CPU_BASED_NMI_WINDOW_EXITING;
 }
 
 static inline bool cpu_has_vmx_preemption_timer(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 1aaec4d19e1b..ce54f13d8da1 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2487,10 +2487,12 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 	      CPU_BASED_MWAIT_EXITING |
 	      CPU_BASED_MONITOR_EXITING |
 	      CPU_BASED_INVLPG_EXITING |
-	      CPU_BASED_RDPMC_EXITING;
+	      CPU_BASED_RDPMC_EXITING |
+	      CPU_BASED_INTR_WINDOW_EXITING;
 
 	opt = CPU_BASED_TPR_SHADOW |
 	      CPU_BASED_USE_MSR_BITMAPS |
+	      CPU_BASED_NMI_WINDOW_EXITING |
 	      CPU_BASED_ACTIVATE_SECONDARY_CONTROLS |
 	      CPU_BASED_ACTIVATE_TERTIARY_CONTROLS;
 	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
@@ -4299,6 +4301,10 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx)
 {
 	u32 exec_control = vmcs_config.cpu_based_exec_ctrl;
 
+	/* INTR_WINDOW_EXITING and NMI_WINDOW_EXITING are toggled dynamically */
+	exec_control &= ~(CPU_BASED_INTR_WINDOW_EXITING |
+			  CPU_BASED_NMI_WINDOW_EXITING);
+
 	if (vmx->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)
 		exec_control &= ~CPU_BASED_MOV_DR_EXITING;
 
-- 
2.35.3