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Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Fri, 15 Sep 2023 17:30:58 -0700
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Subject: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO
From:   Sean Christopherson <seanjc@google.com>
To:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        Huacai Chen <chenhuacai@kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Anup Patel <anup@brainfault.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Tony Krowiak <akrowiak@linux.ibm.com>,
        Halil Pasic <pasic@linux.ibm.com>,
        Jason Herne <jjherne@linux.ibm.com>,
        Harald Freudenberger <freude@linux.ibm.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Andy Lutomirski <luto@kernel.org>
Cc:     linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-mips@vger.kernel.org, kvm@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org,
        linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        Anish Ghulati <aghulati@google.com>,
        Venkatesh Srinivas <venkateshs@chromium.org>,
        Andrew Thornton <andrewth@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Drop KVM's KVM_VFIO Kconfig, and instead compile in VFIO support if
and only if VFIO itself is enabled.  Similar to the recent change to have
VFIO stop looking at HAVE_KVM, compiling in support for talking to VFIO
just because the architecture supports VFIO is nonsensical.

This fixes a bug where RISC-V doesn't select KVM_VFIO, i.e. would silently
fail to do connect KVM and VFIO, even though RISC-V supports VFIO.  The
bug is benign as the only driver in all of Linux that actually uses the
KVM reference provided by VFIO is KVM-GT, which is x86/Intel specific.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/arm64/kvm/Kconfig   | 1 -
 arch/powerpc/kvm/Kconfig | 1 -
 arch/s390/kvm/Kconfig    | 1 -
 arch/x86/kvm/Kconfig     | 1 -
 virt/kvm/Kconfig         | 3 ---
 virt/kvm/Makefile.kvm    | 4 +++-
 virt/kvm/vfio.h          | 2 +-
 7 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 83c1e09be42e..2b5c332f157d 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -28,7 +28,6 @@ menuconfig KVM
 	select KVM_MMIO
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select KVM_XFER_TO_GUEST_WORK
-	select KVM_VFIO
 	select HAVE_KVM_EVENTFD
 	select HAVE_KVM_IRQFD
 	select HAVE_KVM_DIRTY_RING_ACQ_REL
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index 902611954200..c4beb49c0eb2 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -22,7 +22,6 @@ config KVM
 	select PREEMPT_NOTIFIERS
 	select HAVE_KVM_EVENTFD
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
-	select KVM_VFIO
 	select IRQ_BYPASS_MANAGER
 	select HAVE_KVM_IRQ_BYPASS
 	select INTERVAL_TREE
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index 45fdf2a9b2e3..459d536116a6 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -31,7 +31,6 @@ config KVM
 	select HAVE_KVM_IRQ_ROUTING
 	select HAVE_KVM_INVALID_WAKEUPS
 	select HAVE_KVM_NO_POLL
-	select KVM_VFIO
 	select INTERVAL_TREE
 	select MMU_NOTIFIER
 	help
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index ed90f148140d..0f01e5600b5f 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -45,7 +45,6 @@ config KVM
 	select HAVE_KVM_NO_POLL
 	select KVM_XFER_TO_GUEST_WORK
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
-	select KVM_VFIO
 	select INTERVAL_TREE
 	select HAVE_KVM_PM_NOTIFIER if PM
 	select KVM_GENERIC_HARDWARE_ENABLING
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 484d0873061c..f0be3b55cea6 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -59,9 +59,6 @@ config HAVE_KVM_MSI
 config HAVE_KVM_CPU_RELAX_INTERCEPT
        bool
 
-config KVM_VFIO
-       bool
-
 config HAVE_KVM_INVALID_WAKEUPS
        bool
 
diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
index 2c27d5d0c367..29373b59d89a 100644
--- a/virt/kvm/Makefile.kvm
+++ b/virt/kvm/Makefile.kvm
@@ -6,7 +6,9 @@
 KVM ?= ../../../virt/kvm
 
 kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
-kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
+ifdef CONFIG_VFIO
+kvm-y += $(KVM)/vfio.o
+endif
 kvm-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
 kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
 kvm-$(CONFIG_HAVE_KVM_IRQ_ROUTING) += $(KVM)/irqchip.o
diff --git a/virt/kvm/vfio.h b/virt/kvm/vfio.h
index e130a4a03530..af475a323965 100644
--- a/virt/kvm/vfio.h
+++ b/virt/kvm/vfio.h
@@ -2,7 +2,7 @@
 #ifndef __KVM_VFIO_H
 #define __KVM_VFIO_H
 
-#ifdef CONFIG_KVM_VFIO
+#if IS_ENABLED(CONFIG_KVM) && IS_ENABLED(CONFIG_VFIO)
 int kvm_vfio_ops_init(void);
 void kvm_vfio_ops_exit(void);
 #else
-- 
2.42.0.459.ge4e396fd5e-goog