[PATCH] kvm: Allow build-time configuration of KVM device assignment

From: Alex Williamson
Date: Tue Apr 16 2013 - 15:50:09 EST

We hope to at some point deprecate KVM legacy device assignment in
favor of VFIO-based assignment. Towards that end, allow legacy
device assignment to be deconfigured.

Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---

This depends on Alex Graf's irqfd generalization series to remove
IRQ routing code from assigned-dev.c.

arch/ia64/include/uapi/asm/kvm.h | 1 -
arch/ia64/kvm/Kconfig | 13 +++++++++++--
arch/ia64/kvm/Makefile | 6 +++---
arch/ia64/kvm/kvm-ia64.c | 2 --
arch/x86/include/uapi/asm/kvm.h | 1 -
arch/x86/kvm/Kconfig | 13 +++++++++++--
arch/x86/kvm/Makefile | 5 +++--
arch/x86/kvm/x86.c | 6 ++++--
include/linux/kvm_host.h | 30 ++++++++----------------------
include/uapi/linux/kvm.h | 4 ----
10 files changed, 40 insertions(+), 41 deletions(-)

diff --git a/arch/ia64/include/uapi/asm/kvm.h b/arch/ia64/include/uapi/asm/kvm.h
index ec6c6b3..99503c2 100644
--- a/arch/ia64/include/uapi/asm/kvm.h
+++ b/arch/ia64/include/uapi/asm/kvm.h
@@ -27,7 +27,6 @@
/* Select x86 specific features in <linux/kvm.h> */
#define __KVM_HAVE_IOAPIC
#define __KVM_HAVE_IRQ_LINE
-#define __KVM_HAVE_DEVICE_ASSIGNMENT

/* Architectural interrupt line count. */
#define KVM_NR_INTERRUPTS 256
diff --git a/arch/ia64/kvm/Kconfig b/arch/ia64/kvm/Kconfig
index 2cd225f..e792664 100644
--- a/arch/ia64/kvm/Kconfig
+++ b/arch/ia64/kvm/Kconfig
@@ -21,8 +21,6 @@ config KVM
tristate "Kernel-based Virtual Machine (KVM) support"
depends on BROKEN
depends on HAVE_KVM && MODULES
- # for device assignment:
- depends on PCI
depends on BROKEN
select PREEMPT_NOTIFIERS
select ANON_INODES
@@ -50,6 +48,17 @@ config KVM_INTEL
Provides support for KVM on Itanium 2 processors equipped with the VT
extensions.

+config KVM_DEVICE_ASSIGNMENT
+ bool "KVM legacy PCI device assignment support"
+ depends on KVM && PCI && IOMMU_API
+ default y
+ ---help---
+ Provide support for legacy PCI device assignment through KVM. The
+ kernel now also supports a full featured userspace device driver
+ framework through VFIO, which supersedes much of this support.
+
+ If unsure, say Y.
+
source drivers/vhost/Kconfig

endif # VIRTUALIZATION
diff --git a/arch/ia64/kvm/Makefile b/arch/ia64/kvm/Makefile
index db3d7c5..1a40537 100644
--- a/arch/ia64/kvm/Makefile
+++ b/arch/ia64/kvm/Makefile
@@ -49,10 +49,10 @@ ccflags-y := -Ivirt/kvm -Iarch/ia64/kvm/
asflags-y := -Ivirt/kvm -Iarch/ia64/kvm/

common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o \
- coalesced_mmio.o irq_comm.o assigned-dev.o)
+ coalesced_mmio.o irq_comm.o)

-ifeq ($(CONFIG_IOMMU_API),y)
-common-objs += $(addprefix ../../../virt/kvm/, iommu.o)
+ifeq ($(CONFIG_KVM_DEVICE_ASSIGNMENT),y)
+common-objs += $(addprefix ../../../virt/kvm/, assigned-dev.o iommu.o)
endif

kvm-objs := $(common-objs) kvm-ia64.o kvm_fw.o
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 7a54455..a21c2c5 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1366,9 +1366,7 @@ void kvm_arch_sync_events(struct kvm *kvm)
void kvm_arch_destroy_vm(struct kvm *kvm)
{
kvm_iommu_unmap_guest(kvm);
-#ifdef KVM_CAP_DEVICE_ASSIGNMENT
kvm_free_all_assigned_devices(kvm);
-#endif
kfree(kvm->arch.vioapic);
kvm_release_vm_pages(kvm);
}
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 923478e..63e6622 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -30,7 +30,6 @@
#define __KVM_HAVE_IOAPIC
#define __KVM_HAVE_IRQCHIP
#define __KVM_HAVE_IRQ_LINE
-#define __KVM_HAVE_DEVICE_ASSIGNMENT
#define __KVM_HAVE_MSI
#define __KVM_HAVE_USER_NMI
#define __KVM_HAVE_GUEST_DEBUG
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 586f000..46e0832 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -21,8 +21,6 @@ config KVM
tristate "Kernel-based Virtual Machine (KVM) support"
depends on HAVE_KVM
depends on HIGH_RES_TIMERS
- # for device assignment:
- depends on PCI
# for TASKSTATS/TASK_DELAY_ACCT:
depends on NET
select PREEMPT_NOTIFIERS
@@ -82,6 +80,17 @@ config KVM_MMU_AUDIT
This option adds a R/W kVM module parameter 'mmu_audit', which allows
audit KVM MMU at runtime.

+config KVM_DEVICE_ASSIGNMENT
+ bool "KVM legacy PCI device assignment support"
+ depends on KVM && PCI && IOMMU_API
+ default y
+ ---help---
+ Provide support for legacy PCI device assignment through KVM. The
+ kernel now also supports a full featured userspace device driver
+ framework through VFIO, which supersedes much of this support.
+
+ If unsure, say Y.
+
# OK, it's a little counter-intuitive to do this, but it puts it neatly under
# the virtualization menu.
source drivers/vhost/Kconfig
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index a797b8e..d609e1d 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -7,8 +7,9 @@ CFLAGS_vmx.o := -I.

kvm-y += $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o \
coalesced_mmio.o irq_comm.o eventfd.o \
- assigned-dev.o irqchip.o)
-kvm-$(CONFIG_IOMMU_API) += $(addprefix ../../../virt/kvm/, iommu.o)
+ irqchip.o)
+kvm-$(CONFIG_KVM_DEVICE_ASSIGNMENT) += $(addprefix ../../../virt/kvm/, \
+ assigned-dev.o iommu.o)
kvm-$(CONFIG_KVM_ASYNC_PF) += $(addprefix ../../../virt/kvm/, async_pf.o)

kvm-y += x86.o mmu.o emulate.o i8259.o irq.o lapic.o \
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9d9904f..86b9217 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2492,7 +2492,6 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_USER_NMI:
case KVM_CAP_REINJECT_CONTROL:
case KVM_CAP_IRQ_INJECT_STATUS:
- case KVM_CAP_ASSIGN_DEV_IRQ:
case KVM_CAP_IRQFD:
case KVM_CAP_IOEVENTFD:
case KVM_CAP_PIT2:
@@ -2510,9 +2509,12 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_XSAVE:
case KVM_CAP_ASYNC_PF:
case KVM_CAP_GET_TSC_KHZ:
- case KVM_CAP_PCI_2_3:
case KVM_CAP_KVMCLOCK_CTRL:
case KVM_CAP_READONLY_MEM:
+#ifdef CONFIG_KVM_DEVICE_ASSIGNMENT
+ case KVM_CAP_ASSIGN_DEV_IRQ:
+ case KVM_CAP_PCI_2_3:
+#endif
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8b25ea2..3358428 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -667,7 +667,6 @@ static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)

int kvm_arch_init_vm(struct kvm *kvm, unsigned long type);
void kvm_arch_destroy_vm(struct kvm *kvm);
-void kvm_free_all_assigned_devices(struct kvm *kvm);
void kvm_arch_sync_events(struct kvm *kvm);

int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);
@@ -736,7 +735,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
/* For vcpu->arch.iommu_flags */
#define KVM_IOMMU_CACHE_COHERENCY 0x1

-#ifdef CONFIG_IOMMU_API
+#ifdef CONFIG_KVM_DEVICE_ASSIGNMENT
int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot);
void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot);
int kvm_iommu_map_guest(struct kvm *kvm);
@@ -745,7 +744,7 @@ int kvm_assign_device(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev);
int kvm_deassign_device(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev);
-#else /* CONFIG_IOMMU_API */
+#else
static inline int kvm_iommu_map_pages(struct kvm *kvm,
struct kvm_memory_slot *slot)
{
@@ -757,28 +756,11 @@ static inline void kvm_iommu_unmap_pages(struct kvm *kvm,
{
}

-static inline int kvm_iommu_map_guest(struct kvm *kvm)
-{
- return -ENODEV;
-}
-
static inline int kvm_iommu_unmap_guest(struct kvm *kvm)
{
return 0;
}
-
-static inline int kvm_assign_device(struct kvm *kvm,
- struct kvm_assigned_dev_kernel *assigned_dev)
-{
- return 0;
-}
-
-static inline int kvm_deassign_device(struct kvm *kvm,
- struct kvm_assigned_dev_kernel *assigned_dev)
-{
- return 0;
-}
-#endif /* CONFIG_IOMMU_API */
+#endif

static inline void __guest_enter(void)
{
@@ -1032,11 +1014,13 @@ static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }

#endif

-#ifdef __KVM_HAVE_DEVICE_ASSIGNMENT
+#ifdef CONFIG_KVM_DEVICE_ASSIGNMENT

long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
unsigned long arg);

+void kvm_free_all_assigned_devices(struct kvm *kvm);
+
#else

static inline long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
@@ -1045,6 +1029,8 @@ static inline long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
return -ENOTTY;
}

+static inline void kvm_free_all_assigned_devices(struct kvm *kvm) {}
+
#endif

static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index c38d269..d647b56 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -561,9 +561,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_MP_STATE 14
#define KVM_CAP_COALESCED_MMIO 15
#define KVM_CAP_SYNC_MMU 16 /* Changes to host mmap are reflected in guest */
-#ifdef __KVM_HAVE_DEVICE_ASSIGNMENT
#define KVM_CAP_DEVICE_ASSIGNMENT 17
-#endif
#define KVM_CAP_IOMMU 18
#ifdef __KVM_HAVE_MSI
#define KVM_CAP_DEVICE_MSI 20
@@ -583,9 +581,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_IRQ_ROUTING 25
#endif
#define KVM_CAP_IRQ_INJECT_STATUS 26
-#ifdef __KVM_HAVE_DEVICE_ASSIGNMENT
#define KVM_CAP_DEVICE_DEASSIGNMENT 27
-#endif
#ifdef __KVM_HAVE_MSIX
#define KVM_CAP_DEVICE_MSIX 28
#endif

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