From d2e19368848ce6065daa785efca26faed54732b6 Mon Sep 17 00:00:00 2001 From: James Morse Date: Tue, 25 Apr 2017 18:02:44 +0100 Subject: KVM: arm: Restore banked registers and physical timer access on hyp_panic() When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. This looks like it was copied from arm64, the 32bit KVM panic code needs to restore the host's banked registers too. At some point panic() touches the physical timer/counter, this will trap back to HYP. If we're lucky, we panic again. Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the guest registers and disables the traps for the host. Fixes: c36b6db5f3e4 ("ARM: KVM: Add panic handling code") Signed-off-by: James Morse Reviewed-by: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/kvm/hyp/switch.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c index 92678b7bd046..c8f15bb5c8b3 100644 --- a/arch/arm/kvm/hyp/switch.c +++ b/arch/arm/kvm/hyp/switch.c @@ -235,8 +235,10 @@ void __hyp_text __noreturn __hyp_panic(int cause) vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR); host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + __timer_save_state(vcpu); __deactivate_traps(vcpu); __deactivate_vm(vcpu); + __banked_restore_state(host_ctxt); __sysreg_restore_state(host_ctxt); } -- cgit v1.2.3 From abd7229626b9339e378a8cfcdebe0c0943b06a7f Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sat, 6 May 2017 20:01:24 +0200 Subject: KVM: arm/arm64: Simplify active_change_prepare and plug race We don't need to stop a specific VCPU when changing the active state, because private IRQs can only be modified by a running VCPU for the VCPU itself and it is therefore already stopped. However, it is also possible for two VCPUs to be modifying the active state of SPIs at the same time, which can cause the thread being stuck in the loop that checks other VCPU threads for a potentially very long time, or to modify the active state of a running VCPU. Fix this by serializing all accesses to setting and clearing the active state of interrupts using the KVM mutex. Reported-by: Andrew Jones Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier --- arch/arm/include/asm/kvm_host.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index f0e66577ce05..12274d46df70 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -233,8 +233,6 @@ struct kvm_vcpu *kvm_arm_get_running_vcpu(void); struct kvm_vcpu __percpu **kvm_get_running_vcpus(void); void kvm_arm_halt_guest(struct kvm *kvm); void kvm_arm_resume_guest(struct kvm *kvm); -void kvm_arm_halt_vcpu(struct kvm_vcpu *vcpu); -void kvm_arm_resume_vcpu(struct kvm_vcpu *vcpu); int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices); unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu); -- cgit v1.2.3 From 2387149eade25f32dcf1398811b3d0293181d005 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 4 Jun 2017 14:43:51 +0200 Subject: KVM: improve arch vcpu request defining Marc Zyngier suggested that we define the arch specific VCPU request base, rather than requiring each arch to remember to start from 8. That suggestion, along with Radim Krcmar's recent VCPU request flag addition, snowballed into defining something of an arch VCPU request defining API. No functional change. (Looks like x86 is running out of arch VCPU request bits. Maybe someday we'll need to extend to 64.) Signed-off-by: Andrew Jones Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 12274d46df70..c556babe467c 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -44,7 +44,8 @@ #define KVM_MAX_VCPUS VGIC_V2_MAX_CPUS #endif -#define KVM_REQ_VCPU_EXIT (8 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_VCPU_EXIT \ + KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode); int __attribute_const__ kvm_target_cpu(void); -- cgit v1.2.3 From 6a6d73be12fbe492d0678cd84d3b35e2bc9698e4 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 4 Jun 2017 14:43:54 +0200 Subject: KVM: arm/arm64: properly use vcpu requests arm/arm64 already has one VCPU request used when setting pause, but it doesn't properly check requests in VCPU RUN. Check it and also make sure we set vcpu->mode at the appropriate time (before the check) and with the appropriate barriers. See Documentation/virtual/kvm/vcpu-requests.rst. Also make sure we don't leave any vcpu requests we don't intend to handle later set in the request bitmap. If we don't clear them, then kvm_request_pending() may return true when it shouldn't. Using VCPU requests properly fixes a small race where pause could get set just as a VCPU was entering guest mode. Signed-off-by: Andrew Jones Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/kvm/handle_exit.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm') diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 5fd7968cdae9..a2b4f7b82356 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -72,6 +72,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) trace_kvm_wfx(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; kvm_vcpu_block(vcpu); + kvm_clear_request(KVM_REQ_UNHALT, vcpu); } kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); -- cgit v1.2.3 From 7b244e2be654d90d77800015d23395357dbc82ba Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 4 Jun 2017 14:43:58 +0200 Subject: KVM: arm/arm64: change exit request to sleep request A request called EXIT is too generic. All requests are meant to cause exits, but different requests have different flags. Let's not make it difficult to decide if the EXIT request is correct for some case by just always providing unique requests for each case. This patch changes EXIT to SLEEP, because that's what the request is asking the VCPU to do. Signed-off-by: Andrew Jones Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index c556babe467c..fdd644c01c89 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -44,7 +44,7 @@ #define KVM_MAX_VCPUS VGIC_V2_MAX_CPUS #endif -#define KVM_REQ_VCPU_EXIT \ +#define KVM_REQ_SLEEP \ KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode); -- cgit v1.2.3 From 325f9c649c8a4e447e4d3babacc7a60b75012d5d Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 4 Jun 2017 14:43:59 +0200 Subject: KVM: arm/arm64: use vcpu requests for irq injection Don't use request-less VCPU kicks when injecting IRQs, as a VCPU kick meant to trigger the interrupt injection could be sent while the VCPU is outside guest mode, which means no IPI is sent, and after it has called kvm_vgic_flush_hwstate(), meaning it won't see the updated GIC state until its next exit some time later for some other reason. The receiving VCPU only needs to check this request in VCPU RUN to handle it. By checking it, if it's pending, a memory barrier will be issued that ensures all state is visible. See "Ensuring Requests Are Seen" of Documentation/virtual/kvm/vcpu-requests.rst Signed-off-by: Andrew Jones Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index fdd644c01c89..00ad56ee6455 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -46,6 +46,7 @@ #define KVM_REQ_SLEEP \ KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_IRQ_PENDING KVM_ARCH_REQ(1) u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode); int __attribute_const__ kvm_target_cpu(void); -- cgit v1.2.3 From 2227e43930278a53054046f9746cba69a1379639 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Tue, 2 May 2017 15:17:59 +0200 Subject: KVM: arm: Handle VCPU device attributes in guest.c As we are about to support VCPU attributes to set the timer IRQ numbers in guest.c, move the static inlines for the VCPU attributes handlers from the header file to guest.c. Signed-off-by: Christoffer Dall Acked-by: Marc Zyngier --- arch/arm/include/asm/kvm_host.h | 22 +++++++-------------- arch/arm/kvm/guest.c | 42 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 15 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 00ad56ee6455..127e2dd2e21c 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -291,20 +291,12 @@ static inline void kvm_arm_init_debug(void) {} static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} -static inline int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, - struct kvm_device_attr *attr) -{ - return -ENXIO; -} -static inline int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, - struct kvm_device_attr *attr) -{ - return -ENXIO; -} -static inline int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, - struct kvm_device_attr *attr) -{ - return -ENXIO; -} + +int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr); +int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr); +int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr); #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c index fa6182a40941..acea05e9db4e 100644 --- a/arch/arm/kvm/guest.c +++ b/arch/arm/kvm/guest.c @@ -301,3 +301,45 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, { return -EINVAL; } + +int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr) +{ + int ret; + + switch (attr->group) { + default: + ret = -ENXIO; + break; + } + + return ret; +} + +int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr) +{ + int ret; + + switch (attr->group) { + default: + ret = -ENXIO; + break; + } + + return ret; +} + +int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr) +{ + int ret; + + switch (attr->group) { + default: + ret = -ENXIO; + break; + } + + return ret; +} -- cgit v1.2.3 From 85e69ad7f2cc6dd829987a70cf32785b1d8c8b27 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Tue, 2 May 2017 20:14:06 +0200 Subject: KVM: arm/arm64: Move timer IRQ default init to arch_timer.c We currently initialize the arch timer IRQ numbers from the reset code, presumably because we once intended to model multiple CPU or SoC types from within the kernel and have hard-coded reset values in the reset code. As we are moving towards userspace being in charge of more fine-grained CPU emulation and stitching together the pieces needed to emulate a particular type of CPU, we should no longer have a tight coupling between resetting a VCPU and setting IRQ numbers. Therefore, move the logic to define and use the default IRQ numbers to the timer code and set the IRQ number immediately when creating the VCPU. Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier --- arch/arm/kvm/reset.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/kvm/reset.c b/arch/arm/kvm/reset.c index 1da8b2d14550..5ed0c3ee33d6 100644 --- a/arch/arm/kvm/reset.c +++ b/arch/arm/kvm/reset.c @@ -37,16 +37,6 @@ static struct kvm_regs cortexa_regs_reset = { .usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT, }; -static const struct kvm_irq_level cortexa_ptimer_irq = { - { .irq = 30 }, - .level = 1, -}; - -static const struct kvm_irq_level cortexa_vtimer_irq = { - { .irq = 27 }, - .level = 1, -}; - /******************************************************************************* * Exported reset function @@ -62,16 +52,12 @@ static const struct kvm_irq_level cortexa_vtimer_irq = { int kvm_reset_vcpu(struct kvm_vcpu *vcpu) { struct kvm_regs *reset_regs; - const struct kvm_irq_level *cpu_vtimer_irq; - const struct kvm_irq_level *cpu_ptimer_irq; switch (vcpu->arch.target) { case KVM_ARM_TARGET_CORTEX_A7: case KVM_ARM_TARGET_CORTEX_A15: reset_regs = &cortexa_regs_reset; vcpu->arch.midr = read_cpuid_id(); - cpu_vtimer_irq = &cortexa_vtimer_irq; - cpu_ptimer_irq = &cortexa_ptimer_irq; break; default: return -ENODEV; @@ -84,5 +70,5 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) kvm_reset_coprocs(vcpu); /* Reset arch_timer context */ - return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq, cpu_ptimer_irq); + return kvm_timer_vcpu_reset(vcpu); } -- cgit v1.2.3 From 99a1db7a2c9b2ecb9a801cee3f6a7a71945a2fca Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Tue, 2 May 2017 20:19:15 +0200 Subject: KVM: arm/arm64: Allow setting the timer IRQ numbers from userspace First we define an ABI using the vcpu devices that lets userspace set the interrupt numbers for the various timers on both the 32-bit and 64-bit KVM/ARM implementations. Second, we add the definitions for the groups and attributes introduced by the above ABI. (We add the PMU define on the 32-bit side as well for symmetry and it may get used some day.) Third, we set up the arch-specific vcpu device operation handlers to call into the timer code for anything related to the KVM_ARM_VCPU_TIMER_CTRL group. Fourth, we implement support for getting and setting the timer interrupt numbers using the above defined ABI in the arch timer code. Fifth, we introduce error checking upon enabling the arch timer (which is called when first running a VCPU) to check that all VCPUs are configured to use the same PPI for the timer (as mandated by the architecture) and that the virtual and physical timers are not configured to use the same IRQ number. Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier --- arch/arm/include/uapi/asm/kvm.h | 8 ++++++++ arch/arm/kvm/guest.c | 9 +++++++++ 2 files changed, 17 insertions(+) (limited to 'arch/arm') diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 5e3c673fa3f4..5db2d4c6a55f 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -203,6 +203,14 @@ struct kvm_arch_memory_slot { #define KVM_DEV_ARM_VGIC_LINE_LEVEL_INTID_MASK 0x3ff #define VGIC_LEVEL_INFO_LINE_LEVEL 0 +/* Device Control API on vcpu fd */ +#define KVM_ARM_VCPU_PMU_V3_CTRL 0 +#define KVM_ARM_VCPU_PMU_V3_IRQ 0 +#define KVM_ARM_VCPU_PMU_V3_INIT 1 +#define KVM_ARM_VCPU_TIMER_CTRL 1 +#define KVM_ARM_VCPU_TIMER_IRQ_VTIMER 0 +#define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1 + #define KVM_DEV_ARM_VGIC_CTRL_INIT 0 #define KVM_DEV_ARM_ITS_SAVE_TABLES 1 #define KVM_DEV_ARM_ITS_RESTORE_TABLES 2 diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c index acea05e9db4e..1e0784ebbfd6 100644 --- a/arch/arm/kvm/guest.c +++ b/arch/arm/kvm/guest.c @@ -308,6 +308,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, int ret; switch (attr->group) { + case KVM_ARM_VCPU_TIMER_CTRL: + ret = kvm_arm_timer_set_attr(vcpu, attr); + break; default: ret = -ENXIO; break; @@ -322,6 +325,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, int ret; switch (attr->group) { + case KVM_ARM_VCPU_TIMER_CTRL: + ret = kvm_arm_timer_get_attr(vcpu, attr); + break; default: ret = -ENXIO; break; @@ -336,6 +342,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, int ret; switch (attr->group) { + case KVM_ARM_VCPU_TIMER_CTRL: + ret = kvm_arm_timer_has_attr(vcpu, attr); + break; default: ret = -ENXIO; break; -- cgit v1.2.3