From 8409a06f2a2c0baeb6e6ff020b2c5a4592b3078d Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sat, 17 Jun 2017 01:09:19 -0700 Subject: KVM: arm/arm64: Make timer_arm and timer_disarm helpers more generic We are about to add an additional soft timer to the arch timer state for a VCPU and would like to be able to reuse the functions to program and cancel a timer, so we make them slightly more generic and rename to make it more clear that these functions work on soft timers and not the hardware resource that this code is managing. The armed flag on the timer state is only used to assert a condition, and we don't rely on this assertion in any meaningful way, so we can simply get rid of this flack and slightly reduce complexity. Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- include/kvm/arm_arch_timer.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index f0053f884b4a..d0beae98f755 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -48,9 +48,6 @@ struct arch_timer_cpu { /* Work queued with the above timer expires */ struct work_struct expired; - /* Background timer active */ - bool armed; - /* Is the timer enabled */ bool enabled; }; -- cgit v1.2.3 From 14d61fa98f03cb01f3aea7e3069fdf460caf5587 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sat, 17 Jun 2017 07:33:02 -0700 Subject: KVM: arm/arm64: Rename soft timer to bg_timer As we are about to introduce a separate hrtimer for the physical timer, call this timer bg_timer, because we refer to this timer as the background timer in the code and comments elsewhere. Signed-off-by: Christoffer Dall Acked-by: Marc Zyngier --- include/kvm/arm_arch_timer.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index d0beae98f755..0eed5bc9fd5e 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -43,7 +43,7 @@ struct arch_timer_cpu { struct arch_timer_context ptimer; /* Background timer used when the guest is not running */ - struct hrtimer timer; + struct hrtimer bg_timer; /* Work queued with the above timer expires */ struct work_struct expired; -- cgit v1.2.3 From f2a2129e0ac8d8fa79c3f85425c36f6e3368f022 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sun, 18 Jun 2017 00:32:08 -0700 Subject: KVM: arm/arm64: Use separate timer for phys timer emulation We were using the same hrtimer for emulating the physical timer and for making sure a blocking VCPU thread would be eventually woken up. That worked fine in the previous arch timer design, but as we are about to actually use the soft timer expire function for the physical timer emulation, change the logic to use a dedicated hrtimer. This has the added benefit of not having to cancel any work in the sync path, which in turn allows us to run the flush and sync with IRQs disabled. Note that the hrtimer used to program the host kernel's timer to generate an exit from the guest when the emulated physical timer fires never has to inject any work, and to share the soft_timer_cancel() function with the bg_timer, we change the function to only cancel any pending work if the pointer to the work struct is not null. Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- include/kvm/arm_arch_timer.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 0eed5bc9fd5e..184c3ef2df93 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -48,6 +48,9 @@ struct arch_timer_cpu { /* Work queued with the above timer expires */ struct work_struct expired; + /* Physical timer emulation */ + struct hrtimer phys_timer; + /* Is the timer enabled */ bool enabled; }; -- cgit v1.2.3 From b103cc3f10c06fb81faacd4ee6f88bbd21246073 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sun, 16 Oct 2016 20:30:38 +0200 Subject: KVM: arm/arm64: Avoid timer save/restore in vcpu entry/exit We don't need to save and restore the hardware timer state and examine if it generates interrupts on on every entry/exit to the guest. The timer hardware is perfectly capable of telling us when it has expired by signaling interrupts. When taking a vtimer interrupt in the host, we don't want to mess with the timer configuration, we just want to forward the physical interrupt to the guest as a virtual interrupt. We can use the split priority drop and deactivate feature of the GIC to do this, which leaves an EOI'ed interrupt active on the physical distributor, making sure we don't keep taking timer interrupts which would prevent the guest from running. We can then forward the physical interrupt to the VM using the HW bit in the LR of the GIC, like we do already, which lets the guest directly deactivate both the physical and virtual timer simultaneously, allowing the timer hardware to exit the VM and generate a new physical interrupt when the timer output is again asserted later on. We do need to capture this state when migrating VCPUs between physical CPUs, however, which we use the vcpu put/load functions for, which are called through preempt notifiers whenever the thread is scheduled away from the CPU or called directly if we return from the ioctl to userspace. One caveat is that we have to save and restore the timer state in both kvm_timer_vcpu_[put/load] and kvm_timer_[schedule/unschedule], because we can have the following flows: 1. kvm_vcpu_block 2. kvm_timer_schedule 3. schedule 4. kvm_timer_vcpu_put (preempt notifier) 5. schedule (vcpu thread gets scheduled back) 6. kvm_timer_vcpu_load (preempt notifier) 7. kvm_timer_unschedule And a version where we don't actually call schedule: 1. kvm_vcpu_block 2. kvm_timer_schedule 7. kvm_timer_unschedule Since kvm_timer_[schedule/unschedule] may not be followed by put/load, but put/load also may be called independently, we call the timer save/restore functions from both paths. Since they rely on the loaded flag to never save/restore when unnecessary, this doesn't cause any harm, and we ensure that all invokations of either set of functions work as intended. An added benefit beyond not having to read and write the timer sysregs on every entry and exit is that we no longer have to actively write the active state to the physical distributor, because we configured the irq for the vtimer to only get a priority drop when handling the interrupt in the GIC driver (we called irq_set_vcpu_affinity()), and the interrupt stays active after firing on the host. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall --- include/kvm/arm_arch_timer.h | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 184c3ef2df93..c538f707e1c1 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -31,8 +31,15 @@ struct arch_timer_context { /* Timer IRQ */ struct kvm_irq_level irq; - /* Active IRQ state caching */ - bool active_cleared_last; + /* + * We have multiple paths which can save/restore the timer state + * onto the hardware, so we need some way of keeping track of + * where the latest state is. + * + * loaded == true: State is loaded on the hardware registers. + * loaded == false: State is stored in memory. + */ + bool loaded; /* Virtual offset */ u64 cntvoff; @@ -78,10 +85,15 @@ void kvm_timer_unschedule(struct kvm_vcpu *vcpu); u64 kvm_phys_timer_read(void); +void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu); void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu); void kvm_timer_init_vhe(void); #define vcpu_vtimer(v) (&(v)->arch.timer_cpu.vtimer) #define vcpu_ptimer(v) (&(v)->arch.timer_cpu.ptimer) + +void enable_el1_phys_timer_access(void); +void disable_el1_phys_timer_access(void); + #endif -- cgit v1.2.3 From 7e90c8e5704cbb299d48e7debb1e61614cb12f41 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Tue, 20 Jun 2017 07:56:20 -0700 Subject: KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate Now when both the vtimer and the ptimer when using both the in-kernel vgic emulation and a userspace IRQ chip are driven by the timer signals and at the vcpu load/put boundaries, instead of recomputing the timer state at every entry/exit to/from the guest, we can get entirely rid of the flush hwstate function. Signed-off-by: Christoffer Dall Acked-by: Marc Zyngier --- include/kvm/arm_arch_timer.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index c538f707e1c1..2352f3a4e88b 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -66,7 +66,6 @@ int kvm_timer_hyp_init(void); int kvm_timer_enable(struct kvm_vcpu *vcpu); int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu); void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu); -void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu); void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu); bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu); void kvm_timer_update_run(struct kvm_vcpu *vcpu); -- cgit v1.2.3 From 1c88ab7ec8c53c4d806bb2b6871ddafdebbffa8b Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Fri, 6 Jan 2017 16:07:48 +0100 Subject: KVM: arm/arm64: Rework kvm_timer_should_fire kvm_timer_should_fire() can be called in two different situations from the kvm_vcpu_block(). The first case is before calling kvm_timer_schedule(), used for wait polling, and in this case the VCPU thread is running and the timer state is loaded onto the hardware so all we have to do is check if the virtual interrupt lines are asserted, becasue the timer interrupt handler functions will raise those lines as appropriate. The second case is inside the wait loop of kvm_vcpu_block(), where we have already called kvm_timer_schedule() and therefore the hardware will be disabled and the software view of the timer state is up to date (timer->loaded is false), and so we can simply check if the timer should fire by looking at the software state. Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier --- include/kvm/arm_arch_timer.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 2352f3a4e88b..01ee473517e2 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -78,7 +78,8 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); -bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx); +bool kvm_timer_is_pending(struct kvm_vcpu *vcpu); + void kvm_timer_schedule(struct kvm_vcpu *vcpu); void kvm_timer_unschedule(struct kvm_vcpu *vcpu); -- cgit v1.2.3 From f7a6509fe002e3909cb41c09e807b7f3ca4a361b Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 1 Sep 2017 17:11:43 +0200 Subject: KVM: s390: vsie: use common code functions for pinning We will not see -ENOMEM (gfn_to_hva() will return KVM_ERR_PTR_BAD_PAGE for all errors). So we can also get rid of special handling in the callers of pin_guest_page() and always assume that it is a g2 error. As also kvm_s390_inject_program_int() should never fail, we can simplify pin_scb(), too. Signed-off-by: David Hildenbrand Message-Id: <20170901151143.22714-1-david@redhat.com> Acked-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- include/linux/kvm_host.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6882538eda32..2e754b7c282c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -667,6 +667,7 @@ kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool *writable); void kvm_release_pfn_clean(kvm_pfn_t pfn); +void kvm_release_pfn_dirty(kvm_pfn_t pfn); void kvm_set_pfn_dirty(kvm_pfn_t pfn); void kvm_set_pfn_accessed(kvm_pfn_t pfn); void kvm_get_pfn(kvm_pfn_t pfn); -- cgit v1.2.3 From da9a1446d248f673a8560ce46251ff620214ab7b Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 9 Nov 2017 10:00:45 +0100 Subject: KVM: s390: provide a capability for AIS state migration The AIS capability was introduced in 4.12, while the interface to migrate the state was added in 4.13. Unfortunately it is not possible for userspace to detect the migration capability without creating a flic kvm device. As in QEMU the cpu model detection runs on the "none" machine this will result in cpu model issues regarding the "ais" capability. To get the "ais" capability properly let's add a new KVM capability that tells userspace that AIS states can be migrated. Signed-off-by: Christian Borntraeger Reviewed-by: Cornelia Huck Reviewed-by: David Hildenbrand Acked-by: Halil Pasic --- 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 838887587411..b60595696836 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -930,6 +930,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SMT_POSSIBLE 147 #define KVM_CAP_HYPERV_SYNIC2 148 #define KVM_CAP_HYPERV_VP_INDEX 149 +#define KVM_CAP_S390_AIS_MIGRATION 150 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3