From 0e4524a5d341e719e8ee9ee7db5d58e2c5a4c10e Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 6 Jul 2017 14:44:28 +0200 Subject: KVM: mark vcpu->pid pointer as rcu protected We do use rcu to protect the pid pointer. Mark it as such and adopt all code to use the proper access methods. This was detected by sparse. "virt/kvm/kvm_main.c:2248:15: error: incompatible types in comparison expression (different address spaces)" Signed-off-by: Christian Borntraeger Reviewed-by: Paolo Bonzini --- include/linux/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 0b50e7b35ed4..bcd37b855c66 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -234,7 +234,7 @@ struct kvm_vcpu { int guest_fpu_loaded, guest_xcr0_loaded; struct swait_queue_head wq; - struct pid *pid; + struct pid __rcu *pid; int sigset_active; sigset_t sigset; struct kvm_vcpu_stat stat; -- cgit v1.2.3 From 4a12f95177280a660bda99e81838919b1cc6a91a Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 7 Jul 2017 10:51:38 +0200 Subject: KVM: mark kvm->busses as rcu protected mark kvm->busses as rcu protected and use the correct access function everywhere. found by sparse virt/kvm/kvm_main.c:3490:15: error: incompatible types in comparison expression (different address spaces) virt/kvm/kvm_main.c:3509:15: error: incompatible types in comparison expression (different address spaces) virt/kvm/kvm_main.c:3561:15: error: incompatible types in comparison expression (different address spaces) virt/kvm/kvm_main.c:3644:15: error: incompatible types in comparison expression (different address spaces) Signed-off-by: Christian Borntraeger --- include/linux/kvm_host.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bcd37b855c66..6a164f9eb02c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -404,7 +404,7 @@ struct kvm { int last_boosted_vcpu; struct list_head vm_list; struct mutex lock; - struct kvm_io_bus *buses[KVM_NR_BUSES]; + struct kvm_io_bus __rcu *buses[KVM_NR_BUSES]; #ifdef CONFIG_HAVE_KVM_EVENTFD struct { spinlock_t lock; @@ -473,6 +473,12 @@ struct kvm { #define vcpu_err(vcpu, fmt, ...) \ kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__) +static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx) +{ + return srcu_dereference_check(kvm->buses[idx], &kvm->srcu, + lockdep_is_held(&kvm->slots_lock)); +} + static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i) { /* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case -- cgit v1.2.3 From a80cf7b5f4149753d5f19c872a47e66195b167d4 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 6 Jul 2017 16:17:14 +0200 Subject: KVM: mark memory slots as rcu we access the memslots array via srcu. Mark it as such and use the right access functions also for the freeing of memory slots. Found by sparse: ./include/linux/kvm_host.h:565:16: error: incompatible types in comparison expression (different address spaces) Signed-off-by: Christian Borntraeger Reviewed-by: Paolo Bonzini --- include/linux/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6a164f9eb02c..b3ca77a96b2d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -390,7 +390,7 @@ struct kvm { spinlock_t mmu_lock; struct mutex slots_lock; struct mm_struct *mm; /* userspace tied to this vm */ - struct kvm_memslots *memslots[KVM_ADDRESS_SPACE_NUM]; + struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM]; struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; /* -- cgit v1.2.3 From 7e988b103d0d52190244517edc76e649071284bb Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 7 Jul 2017 15:49:00 +0200 Subject: KVM: use correct accessor function for __kvm_memslots kvm memslots are protected by srcu and not by rcu. We must use srcu_dereference_check instead of rcu_dereference_check. Signed-off-by: Christian Borntraeger Suggested-by: Paolo Bonzini --- include/linux/kvm_host.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b3ca77a96b2d..648b34cabb38 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -568,9 +568,8 @@ void kvm_put_kvm(struct kvm *kvm); static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id) { - return rcu_dereference_check(kvm->memslots[as_id], - srcu_read_lock_held(&kvm->srcu) - || lockdep_is_held(&kvm->slots_lock)); + return srcu_dereference_check(kvm->memslots[as_id], &kvm->srcu, + lockdep_is_held(&kvm->slots_lock)); } static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm) -- cgit v1.2.3 From 949c033694864082db9b3f5304723a6d7407f8e2 Mon Sep 17 00:00:00 2001 From: Gleb Fotengauer-Malinovskiy Date: Tue, 11 Jul 2017 00:22:33 +0300 Subject: KVM: s390: Fix KVM_S390_GET_CMMA_BITS ioctl definition MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In case of KVM_S390_GET_CMMA_BITS, the kernel does not only read struct kvm_s390_cmma_log passed from userspace (which constitutes _IOC_WRITE), it also writes back a return value (which constitutes _IOC_READ) making this an _IOWR ioctl instead of _IOW. Fixes: 4036e387 ("KVM: s390: ioctls to get and set guest storage attributes") Signed-off-by: Gleb Fotengauer-Malinovskiy Acked-by: Christian Borntraeger Signed-off-by: Radim Krčmář --- include/uapi/linux/kvm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index c0b6dfec5f87..ebd604c222d8 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1351,7 +1351,7 @@ struct kvm_s390_ucas_mapping { /* Available with KVM_CAP_X86_SMM */ #define KVM_SMI _IO(KVMIO, 0xb7) /* Available with KVM_CAP_S390_CMMA_MIGRATION */ -#define KVM_S390_GET_CMMA_BITS _IOW(KVMIO, 0xb8, struct kvm_s390_cmma_log) +#define KVM_S390_GET_CMMA_BITS _IOWR(KVMIO, 0xb8, struct kvm_s390_cmma_log) #define KVM_S390_SET_CMMA_BITS _IOW(KVMIO, 0xb9, struct kvm_s390_cmma_log) #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) -- cgit v1.2.3 From efc479e6900c22bad9a2b649d13405ed9cde2d53 Mon Sep 17 00:00:00 2001 From: Roman Kagan Date: Thu, 22 Jun 2017 16:51:01 +0300 Subject: kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a flaw in the Hyper-V SynIC implementation in KVM: when message page or event flags page is enabled by setting the corresponding msr, KVM zeroes it out. This is problematic because on migration the corresponding MSRs are loaded on the destination, so the content of those pages is lost. This went unnoticed so far because the only user of those pages was in-KVM hyperv synic timers, which could continue working despite that zeroing. Newer QEMU uses those pages for Hyper-V VMBus implementation, and zeroing them breaks the migration. Besides, in newer QEMU the content of those pages is fully managed by QEMU, so zeroing them is undesirable even when writing the MSRs from the guest side. To support this new scheme, introduce a new capability, KVM_CAP_HYPERV_SYNIC2, which, when enabled, makes sure that the synic pages aren't zeroed out in KVM. Signed-off-by: Roman Kagan Signed-off-by: Radim Krčmář --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ebd604c222d8..38b2cfbc8112 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -927,6 +927,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_CMMA_MIGRATION 145 #define KVM_CAP_PPC_FWNMI 146 #define KVM_CAP_PPC_SMT_POSSIBLE 147 +#define KVM_CAP_HYPERV_SYNIC2 148 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3 From d3457c877b14aaee8c52923eedf05a3b78af0476 Mon Sep 17 00:00:00 2001 From: Roman Kagan Date: Fri, 14 Jul 2017 17:13:20 +0300 Subject: kvm: x86: hyperv: make VP_INDEX managed by userspace MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hyper-V identifies vCPUs by Virtual Processor Index, which can be queried via HV_X64_MSR_VP_INDEX msr. It is defined by the spec as a sequential number which can't exceed the maximum number of vCPUs per VM. APIC ids can be sparse and thus aren't a valid replacement for VP indices. Current KVM uses its internal vcpu index as VP_INDEX. However, to make it predictable and persistent across VM migrations, the userspace has to control the value of VP_INDEX. This patch achieves that, by storing vp_index explicitly on vcpu, and allowing HV_X64_MSR_VP_INDEX to be set from the host side. For compatibility it's initialized to KVM vcpu index. Also a few variables are renamed to make clear distinction betweed this Hyper-V vp_index and KVM vcpu_id (== APIC id). Besides, a new capability, KVM_CAP_HYPERV_VP_INDEX, is added to allow the userspace to skip attempting msr writes where unsupported, to avoid spamming error logs. Signed-off-by: Roman Kagan Signed-off-by: Radim Krčmář --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 38b2cfbc8112..6cd63c18708a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -928,6 +928,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_FWNMI 146 #define KVM_CAP_PPC_SMT_POSSIBLE 147 #define KVM_CAP_HYPERV_SYNIC2 148 +#define KVM_CAP_HYPERV_VP_INDEX 149 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3