From a7d4b8f2565ad0dfdff9a222d1d87990c73b36e8 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 16 Aug 2016 14:38:24 +0200 Subject: KVM: s390: don't use current->thread.fpu.* when accessing registers As the meaning of these variables and pointers seems to change more frequently, let's directly access our save area, instead of going via current->thread. Right now, this is broken for set/get_fpu. They simply overwrite the host registers, as the pointers to the current save area were turned into the static host save area. Cc: stable@vger.kernel.org # 4.7 Fixes: 3f6813b9a5e0 ("s390/fpu: allocate 'struct fpu' with the task_struct") Reported-by: Hao QingFeng Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index f142215ed30dd1..607ec91966c722 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2231,9 +2231,10 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) return -EINVAL; current->thread.fpu.fpc = fpu->fpc; if (MACHINE_HAS_VX) - convert_fp_to_vx(current->thread.fpu.vxrs, (freg_t *)fpu->fprs); + convert_fp_to_vx((__vector128 *) vcpu->run->s.regs.vrs, + (freg_t *) fpu->fprs); else - memcpy(current->thread.fpu.fprs, &fpu->fprs, sizeof(fpu->fprs)); + memcpy(vcpu->run->s.regs.fprs, &fpu->fprs, sizeof(fpu->fprs)); return 0; } @@ -2242,9 +2243,10 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) /* make sure we have the latest values */ save_fpu_regs(); if (MACHINE_HAS_VX) - convert_vx_to_fp((freg_t *)fpu->fprs, current->thread.fpu.vxrs); + convert_vx_to_fp((freg_t *) fpu->fprs, + (__vector128 *) vcpu->run->s.regs.vrs); else - memcpy(fpu->fprs, current->thread.fpu.fprs, sizeof(fpu->fprs)); + memcpy(fpu->fprs, vcpu->run->s.regs.fprs, sizeof(fpu->fprs)); fpu->fpc = current->thread.fpu.fpc; return 0; } -- cgit 1.2.3-korg From 4d21cef3ea00ba3ac508eb61fb8db70e3e31df67 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 2 Sep 2016 12:33:49 +0200 Subject: KVM: s390: vsie: fix riccbd We store the address of riccbd at the wrong location, overwriting gvrd. This means that our nested guest will not be able to use runtime instrumentation. Also, a memory leak, if our KVM guest actually sets gvrd. Not noticed until now, as KVM guests never make use of gvrd and runtime instrumentation wasn't completely tested yet. Reported-by: Fan Zhang Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Cornelia Huck --- arch/s390/kvm/vsie.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index c106488b41371b..d8673e243f13bf 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -584,7 +584,7 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) /* Validity 0x0044 will be checked by SIE */ if (rc) goto unpin; - scb_s->gvrd = hpa; + scb_s->riccbd = hpa; } return 0; unpin: -- cgit 1.2.3-korg From e12c8f36f3f7a60d55938c5aed5999278fa92bcb Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 30 Aug 2016 16:14:00 +0800 Subject: KVM: lapic: adjust preemption timer correctly when goes TSC backward MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit TSC_OFFSET will be adjusted if discovers TSC backward during vCPU load. The preemption timer, which relies on the guest tsc to reprogram its preemption timer value, is also reprogrammed if vCPU is scheded in to a different pCPU. However, the current implementation reprogram preemption timer before TSC_OFFSET is adjusted to the right value, resulting in the preemption timer firing prematurely. This patch fix it by adjusting TSC_OFFSET before reprogramming preemption timer if TSC backward. Cc: Paolo Bonzini Cc: Radim Krċmář Cc: Yunhong Jiang Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 19f9f9e05c2a81..699f8726539a20 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2743,16 +2743,16 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) if (tsc_delta < 0) mark_tsc_unstable("KVM discovered backwards TSC"); - if (kvm_lapic_hv_timer_in_use(vcpu) && - kvm_x86_ops->set_hv_timer(vcpu, - kvm_get_lapic_tscdeadline_msr(vcpu))) - kvm_lapic_switch_to_sw_timer(vcpu); if (check_tsc_unstable()) { u64 offset = kvm_compute_tsc_offset(vcpu, vcpu->arch.last_guest_tsc); kvm_x86_ops->write_tsc_offset(vcpu, offset); vcpu->arch.tsc_catchup = 1; } + if (kvm_lapic_hv_timer_in_use(vcpu) && + kvm_x86_ops->set_hv_timer(vcpu, + kvm_get_lapic_tscdeadline_msr(vcpu))) + kvm_lapic_switch_to_sw_timer(vcpu); /* * On a host with synchronized TSC, there is no need to update * kvmclock on vcpu->cpu migration -- cgit 1.2.3-korg From d2896d4b55b2e32b423072a4124d7da4dc1e6cb1 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 22 Aug 2016 09:01:17 +0100 Subject: arm: KVM: Fix idmap overlap detection when the kernel is idmap'ed We're trying hard to detect when the HYP idmap overlaps with the HYP va, as it makes the teardown of a cpu dangerous. But there is one case where an overlap is completely safe, which is when the whole of the kernel is idmap'ed, which is likely to happen on 32bit when RAM is at 0x8000000 and we're using a 2G/2G VA split. In that case, we can proceed safely. Reported-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 29d0b23af2a9de..a3faafe70081d9 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1714,7 +1714,8 @@ int kvm_mmu_init(void) kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL)); if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) && - hyp_idmap_start < kern_hyp_va(~0UL)) { + hyp_idmap_start < kern_hyp_va(~0UL) && + hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) { /* * The idmap page is intersecting with the VA space, * it is not safe to continue further. -- cgit 1.2.3-korg From a4497a86fb9b855c5ac8503fdc959393b00bb643 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Thu, 8 Sep 2016 10:15:28 -0400 Subject: x86, clock: Fix kvm guest tsc initialization MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When booting a kvm guest on AMD with the latest kernel the following messages are displayed in the boot log: tsc: Unable to calibrate against PIT tsc: HPET/PMTIMER calibration failed aa297292d708 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID") introduced a change to account for a difference in cpu and tsc frequencies for Intel SKL processors. Before this change the native tsc set x86_platform.calibrate_tsc to native_calibrate_tsc() which is a hardware calibration of the tsc, and in tsc_init() executed tsc_khz = x86_platform.calibrate_tsc(); cpu_khz = tsc_khz; The kvm code changed x86_platform.calibrate_tsc to kvm_get_tsc_khz() and executed the same tsc_init() function. This meant that KVM guests did not execute the native hardware calibration function. After aa297292d708, there are separate native calibrations for cpu_khz and tsc_khz. The code sets x86_platform.calibrate_tsc to native_calibrate_tsc() which is now an Intel specific calibration function, and x86_platform.calibrate_cpu to native_calibrate_cpu() which is the "old" native_calibrate_tsc() function (ie, the native hardware calibration function). tsc_init() now does cpu_khz = x86_platform.calibrate_cpu(); tsc_khz = x86_platform.calibrate_tsc(); if (tsc_khz == 0) tsc_khz = cpu_khz; else if (abs(cpu_khz - tsc_khz) * 10 > tsc_khz) cpu_khz = tsc_khz; The kvm code should not call the hardware initialization in native_calibrate_cpu(), as it isn't applicable for kvm and it didn't do that prior to aa297292d708. This patch resolves this issue by setting x86_platform.calibrate_cpu to kvm_get_tsc_khz(). v2: I had originally set x86_platform.calibrate_cpu to cpu_khz_from_cpuid(), however, pbonzini pointed out that the CPUID leaf in that function is not available in KVM. I have changed the function pointer to kvm_get_tsc_khz(). Fixes: aa297292d708 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID") Signed-off-by: Prarit Bhargava Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Len Brown Cc: "Peter Zijlstra (Intel)" Cc: Borislav Petkov Cc: Adrian Hunter Cc: "Christopher S. Hall" Cc: David Woodhouse Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/x86/kernel/kvmclock.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 1d39bfbd26bb3d..3692249a70f1ed 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -289,6 +289,7 @@ void __init kvmclock_init(void) put_cpu(); x86_platform.calibrate_tsc = kvm_get_tsc_khz; + x86_platform.calibrate_cpu = kvm_get_tsc_khz; x86_platform.get_wallclock = kvm_get_wallclock; x86_platform.set_wallclock = kvm_set_wallclock; #ifdef CONFIG_X86_LOCAL_APIC -- cgit 1.2.3-korg From 293f293637b55db4f9f522a5a72514e98a541076 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Thu, 8 Sep 2016 16:25:49 +0100 Subject: kvm-arm: Unmap shadow pagetables properly On arm/arm64, we depend on the kvm_unmap_hva* callbacks (via mmu_notifiers::invalidate_*) to unmap the stage2 pagetables when the userspace buffer gets unmapped. However, when the Hypervisor process exits without explicit unmap of the guest buffers, the only notifier we get is kvm_arch_flush_shadow_all() (via mmu_notifier::release ) which does nothing on arm. Later this causes us to access pages that were already released [via exit_mmap() -> unmap_vmas()] when we actually get to unmap the stage2 pagetable [via kvm_arch_destroy_vm() -> kvm_free_stage2_pgd()]. This triggers crashes with CONFIG_DEBUG_PAGEALLOC, which unmaps any free'd pages from the linear map. [ 757.644120] Unable to handle kernel paging request at virtual address ffff800661e00000 [ 757.652046] pgd = ffff20000b1a2000 [ 757.655471] [ffff800661e00000] *pgd=00000047fffe3003, *pud=00000047fcd8c003, *pmd=00000047fcc7c003, *pte=00e8004661e00712 [ 757.666492] Internal error: Oops: 96000147 [#3] PREEMPT SMP [ 757.672041] Modules linked in: [ 757.675100] CPU: 7 PID: 3630 Comm: qemu-system-aar Tainted: G D 4.8.0-rc1 #3 [ 757.683240] Hardware name: AppliedMicro X-Gene Mustang Board/X-Gene Mustang Board, BIOS 3.06.15 Aug 19 2016 [ 757.692938] task: ffff80069cdd3580 task.stack: ffff8006adb7c000 [ 757.698840] PC is at __flush_dcache_area+0x1c/0x40 [ 757.703613] LR is at kvm_flush_dcache_pmd+0x60/0x70 [ 757.708469] pc : [] lr : [] pstate: 20000145 ... [ 758.357249] [] __flush_dcache_area+0x1c/0x40 [ 758.363059] [] unmap_stage2_range+0x458/0x5f0 [ 758.368954] [] kvm_free_stage2_pgd+0x34/0x60 [ 758.374761] [] kvm_arch_destroy_vm+0x20/0x68 [ 758.380570] [] kvm_put_kvm+0x210/0x358 [ 758.385860] [] kvm_vm_release+0x2c/0x40 [ 758.391239] [] __fput+0x114/0x2e8 [ 758.396096] [] ____fput+0xc/0x18 [ 758.400869] [] task_work_run+0x108/0x138 [ 758.406332] [] do_exit+0x48c/0x10e8 [ 758.411363] [] do_group_exit+0x6c/0x130 [ 758.416739] [] get_signal+0x284/0xa18 [ 758.421943] [] do_signal+0x158/0x860 [ 758.427060] [] do_notify_resume+0x6c/0x88 [ 758.432608] [] work_pending+0x10/0x14 [ 758.437812] Code: 9ac32042 8b010001 d1000443 8a230000 (d50b7e20) This patch fixes the issue by moving the kvm_free_stage2_pgd() to kvm_arch_flush_shadow_all(). Cc: # 3.9+ Tested-by: Itaru Kitayama Reported-by: Itaru Kitayama Reported-by: James Morse Cc: Marc Zyngier Cc: Catalin Marinas Cc: Christoffer Dall Signed-off-by: Suzuki K Poulose Signed-off-by: Christoffer Dall --- arch/arm/kvm/arm.c | 2 -- arch/arm/kvm/mmu.c | 1 + 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 75f130ef650413..c94b90d437724f 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -158,8 +158,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm) { int i; - kvm_free_stage2_pgd(kvm); - for (i = 0; i < KVM_MAX_VCPUS; ++i) { if (kvm->vcpus[i]) { kvm_arch_vcpu_free(kvm->vcpus[i]); diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index a3faafe70081d9..e9a5c0e0c11543 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1894,6 +1894,7 @@ void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots) void kvm_arch_flush_shadow_all(struct kvm *kvm) { + kvm_free_stage2_pgd(kvm); } void kvm_arch_flush_shadow_memslot(struct kvm *kvm, -- cgit 1.2.3-korg