From: Paolo Bonzini Date: Tue, 12 Dec 2017 16:41:34 +0000 (+0100) Subject: KVM: introduce kvm_arch_vcpu_async_ioctl X-Git-Tag: v4.16-rc1~10^2~45 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=5cb0944c0c66004c0d9006a7f0fba5782ae38f69;p=linux.git KVM: introduce kvm_arch_vcpu_async_ioctl After the vcpu_load/vcpu_put pushdown, the handling of asynchronous VCPU ioctl is already much clearer in that it is obvious that they bypass vcpu_load and vcpu_put. However, it is still not perfect in that the different state of the VCPU mutex is still hidden in the caller. Separate those ioctls into a new function kvm_arch_vcpu_async_ioctl that returns -ENOIOCTLCMD for more "traditional" synchronous ioctls. Cc: James Hogan Cc: Paul Mackerras Cc: Christian Borntraeger Reviewed-by: Christoffer Dall Reviewed-by: Cornelia Huck Suggested-by: Cornelia Huck Signed-off-by: Paolo Bonzini --- diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig index b17447ce8873..76b93a9c8c9b 100644 --- a/arch/mips/kvm/Kconfig +++ b/arch/mips/kvm/Kconfig @@ -22,6 +22,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select KVM_GENERIC_DIRTYLOG_READ_PROTECT + select HAVE_KVM_VCPU_ASYNC_IOCTL select KVM_MMIO select MMU_NOTIFIER select SRCU diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 9200b3def440..2549fdd27ee1 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -903,12 +903,11 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, return r; } -long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, - unsigned long arg) +long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl, + unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = (void __user *)arg; - long r; if (ioctl == KVM_INTERRUPT) { struct kvm_mips_interrupt irq; @@ -921,6 +920,16 @@ long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, return kvm_vcpu_ioctl_interrupt(vcpu, &irq); } + return -ENOIOCTLCMD; +} + +long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, + unsigned long arg) +{ + struct kvm_vcpu *vcpu = filp->private_data; + void __user *argp = (void __user *)arg; + long r; + vcpu_load(vcpu); switch (ioctl) { diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index b12b8eb39c29..f884a0529dfe 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -22,6 +22,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select HAVE_KVM_EVENTFD + select HAVE_KVM_VCPU_ASYNC_IOCTL select SRCU select KVM_VFIO select IRQ_BYPASS_MANAGER diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index ba8134a989c1..66a310779de5 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -1607,12 +1607,11 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, return -EINVAL; } -long kvm_arch_vcpu_ioctl(struct file *filp, - unsigned int ioctl, unsigned long arg) +long kvm_arch_vcpu_async_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = (void __user *)arg; - long r; if (ioctl == KVM_INTERRUPT) { struct kvm_interrupt irq; @@ -1620,6 +1619,15 @@ long kvm_arch_vcpu_ioctl(struct file *filp, return -EFAULT; return kvm_vcpu_ioctl_interrupt(vcpu, &irq); } + return -ENOIOCTLCMD; +} + +long kvm_arch_vcpu_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) +{ + struct kvm_vcpu *vcpu = filp->private_data; + void __user *argp = (void __user *)arg; + long r; vcpu_load(vcpu); diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig index 9a4594e0a1ff..a3dbd459cce9 100644 --- a/arch/s390/kvm/Kconfig +++ b/arch/s390/kvm/Kconfig @@ -23,6 +23,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select HAVE_KVM_CPU_RELAX_INTERCEPT + select HAVE_KVM_VCPU_ASYNC_IOCTL select HAVE_KVM_EVENTFD select KVM_ASYNC_PF select KVM_ASYNC_PF_SYNC diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 9700d71cb691..40f0ae5a883f 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3725,13 +3725,11 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu, return r; } -long kvm_arch_vcpu_ioctl(struct file *filp, - unsigned int ioctl, unsigned long arg) +long kvm_arch_vcpu_async_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = (void __user *)arg; - int idx; - long r; switch (ioctl) { case KVM_S390_IRQ: { @@ -3752,6 +3750,16 @@ long kvm_arch_vcpu_ioctl(struct file *filp, return kvm_s390_inject_vcpu(vcpu, &s390irq); } } + return -ENOIOCTLCMD; +} + +long kvm_arch_vcpu_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) +{ + struct kvm_vcpu *vcpu = filp->private_data; + void __user *argp = (void __user *)arg; + int idx; + long r; vcpu_load(vcpu); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 09de0ff3d677..ac0062b74aed 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1260,4 +1260,16 @@ static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu) } #endif /* CONFIG_HAVE_KVM_INVALID_WAKEUPS */ +#ifdef CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL +long kvm_arch_vcpu_async_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg); +#else +static inline long kvm_arch_vcpu_async_ioctl(struct file *filp, + unsigned int ioctl, + unsigned long arg) +{ + return -ENOIOCTLCMD; +} +#endif /* CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL */ + #endif diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 70691c08e1ed..cca7e065a075 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -51,3 +51,6 @@ config KVM_COMPAT config HAVE_KVM_IRQ_BYPASS bool + +config HAVE_KVM_VCPU_ASYNC_IOCTL + bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 19c184fa1839..b4414842b023 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2544,15 +2544,13 @@ static long kvm_vcpu_ioctl(struct file *filp, if (unlikely(_IOC_TYPE(ioctl) != KVMIO)) return -EINVAL; -#if defined(CONFIG_S390) || defined(CONFIG_PPC) || defined(CONFIG_MIPS) /* - * Special cases: vcpu ioctls that are asynchronous to vcpu execution, - * so vcpu_load() would break it. + * Some architectures have vcpu ioctls that are asynchronous to vcpu + * execution; mutex_lock() would break them. */ - if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_S390_IRQ || ioctl == KVM_INTERRUPT) - return kvm_arch_vcpu_ioctl(filp, ioctl, arg); -#endif - + r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg); + if (r != -ENOIOCTLCMD) + return r; if (mutex_lock_killable(&vcpu->mutex)) return -EINTR;