linux-kernel - [PATCH v2 7/8] KVM: x86: remove SMRAM address space if SMM is not supported

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Message-Id: <20220929172016.319443-8-pbonzini@redhat.com>
Date:   Thu, 29 Sep 2022 13:20:15 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     seanjc@...gle.com, maciej.szmigiero@...cle.com
Subject: [PATCH v2 7/8] KVM: x86: remove SMRAM address space if SMM is not supported

If CONFIG_KVM_SMM is not defined HF_SMM_MASK will always be zero, and
we can spare userspace the hassle of setting up the SMRAM address space
simply by reporting that only one address space is supported.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/include/asm/kvm_host.h | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index cb88da02d965..d11697504471 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1994,11 +1994,14 @@ enum {
 #define HF_SMM_MASK		(1 << 6)
 #define HF_SMM_INSIDE_NMI_MASK	(1 << 7)
 
-#define __KVM_VCPU_MULTIPLE_ADDRESS_SPACE
-#define KVM_ADDRESS_SPACE_NUM 2
-
-#define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
-#define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
+#ifdef CONFIG_KVM_SMM
+# define __KVM_VCPU_MULTIPLE_ADDRESS_SPACE
+# define KVM_ADDRESS_SPACE_NUM 2
+# define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
+# define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
+#else
+# define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, 0)
+#endif
 
 #define KVM_ARCH_WANT_MMU_NOTIFIER
 
-- 
2.31.1