From aea218f3cbbcaac249b6b2c98930a00d6d931f1e Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 26 Jul 2012 10:00:45 +0300 Subject: KVM: PIC: call ack notifiers for irqs that are dropped form irr After commit 242ec97c358256 PIT interrupts are no longer delivered after PIC reset. It happens because PIT injects interrupt only if previous one was acked, but since on PIC reset it is dropped from irr it will never be delivered and hence acknowledged. Fix that by calling ack notifier on PIC reset. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- arch/x86/kvm/i8259.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 1df8fb9e1d5d..e498b18f010c 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -316,6 +316,11 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val) addr &= 1; if (addr == 0) { if (val & 0x10) { + u8 edge_irr = s->irr & ~s->elcr; + int i; + bool found; + struct kvm_vcpu *vcpu; + s->init4 = val & 1; s->last_irr = 0; s->irr &= s->elcr; @@ -333,6 +338,18 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val) if (val & 0x08) pr_pic_unimpl( "level sensitive irq not supported"); + + kvm_for_each_vcpu(i, vcpu, s->pics_state->kvm) + if (kvm_apic_accept_pic_intr(vcpu)) { + found = true; + break; + } + + + if (found) + for (irq = 0; irq < PIC_NUM_PINS/2; irq++) + if (edge_irr & (1 << irq)) + pic_clear_isr(s, irq); } else if (val & 0x08) { if (val & 0x04) s->poll = 1; -- cgit v1.2.3 From 4b6486659a7defef82ea51b276024b3aa357fefc Mon Sep 17 00:00:00 2001 From: Bruce Rogers Date: Fri, 20 Jul 2012 10:44:24 -0600 Subject: KVM: x86: apply kvmclock offset to guest wall clock time When a guest migrates to a new host, the system time difference from the previous host is used in the updates to the kvmclock system time visible to the guest, resulting in a continuation of correct kvmclock based guest timekeeping. The wall clock component of the kvmclock provided time is currently not updated with this same time offset. Since the Linux guest caches the wall clock based time, this discrepency is not noticed until the guest is rebooted. After reboot the guest's time calculations are off. This patch adjusts the wall clock by the kvmclock_offset, resulting in correct guest time after a reboot. Cc: Zachary Amsden Signed-off-by: Bruce Rogers Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/x86.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 59b59508ff07..42bce48f6928 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -925,6 +925,10 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) */ getboottime(&boot); + if (kvm->arch.kvmclock_offset) { + struct timespec ts = ns_to_timespec(kvm->arch.kvmclock_offset); + boot = timespec_sub(boot, ts); + } wc.sec = boot.tv_sec; wc.nsec = boot.tv_nsec; wc.version = version; -- cgit v1.2.3 From aa67f6096c19bcdb1951ef88be3cf3d2118809dc Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 1 Aug 2012 16:48:03 +0300 Subject: KVM: VMX: Fix ds/es corruption on i386 with preemption Commit b2da15ac26a0c ("KVM: VMX: Optimize %ds, %es reload") broke i386 in the following scenario: vcpu_load ... vmx_save_host_state vmx_vcpu_run (ds.rpl, es.rpl cleared by hardware) interrupt push ds, es # pushes bad ds, es schedule vmx_vcpu_put vmx_load_host_state reload ds, es (with __USER_DS) pop ds, es # of other thread's stack iret # other thread runs interrupt push ds, es schedule # back in vcpu thread pop ds, es # now with rpl=0 iret ... vcpu_put resume_userspace iret # clears ds, es due to mismatched rpl (instead of resume_userspace, we might return with SYSEXIT and then take an exception; when the exception IRETs we end up with cleared ds, es) Fix by avoiding the optimization on i386 and reloading ds, es on the lightweight exit path. Reported-by: Chris Clayron Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c39b60707e02..c00f03de1b79 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1488,13 +1488,6 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) loadsegment(ds, vmx->host_state.ds_sel); loadsegment(es, vmx->host_state.es_sel); } -#else - /* - * The sysexit path does not restore ds/es, so we must set them to - * a reasonable value ourselves. - */ - loadsegment(ds, __USER_DS); - loadsegment(es, __USER_DS); #endif reload_tss(); #ifdef CONFIG_X86_64 @@ -6370,6 +6363,19 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) #endif ); +#ifndef CONFIG_X86_64 + /* + * The sysexit path does not restore ds/es, so we must set them to + * a reasonable value ourselves. + * + * We can't defer this to vmx_load_host_state() since that function + * may be executed in interrupt context, which saves and restore segments + * around it, nullifying its effect. + */ + loadsegment(ds, __USER_DS); + loadsegment(es, __USER_DS); +#endif + vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP) | (1 << VCPU_EXREG_RFLAGS) | (1 << VCPU_EXREG_CPL) -- cgit v1.2.3