Re: [PATCH] kvm: Allow build-time configuration of KVM deviceassignment

From: Gleb Natapov
Date: Sun Apr 28 2013 - 06:13:46 EST


On Tue, Apr 16, 2013 at 01:49:18PM -0600, Alex Williamson wrote:
> 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>
Applied, thanks.

> ---
>
> 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

--
Gleb.
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