Hi Christoffer, On 2014/9/26 21:44, Christoffer Dall wrote: > On Fri, Sep 26, 2014 at 12:16:35PM +0200, Christoffer Dall wrote: >> On Fri, Sep 26, 2014 at 05:26:00PM +0800, Shannon Zhao wrote: >>> >>> >>> On 2014/9/26 16:44, Christoffer Dall wrote: >>>> Hi Shannon, >>>> >>>> On Fri, Sep 26, 2014 at 01:57:46PM +0800, Shannon Zhao wrote: >>>>> >>>>> On 2014/9/26 1:49, Christoffer Dall wrote: >>>>>> The sgi values calculated in read_set_clear_sgi_pend_reg() and >>>>>> write_set_clear_sgi_pend_reg() were horribly incorrectly multiplied by 4 >>>>>> with catastrophic results in that subfunctions ended up overwriting >>>>>> memory not allocated for the expected purpose. >>>>>> >>>>>> This showed up as bugs in kfree() and the kernel complaining a lot of >>>>>> you turn on memory debugging. >>>>>> >>>>>> This addresses: http://marc.info/?l=kvm&m=141164910007868&w=2 >>>>>> >>>>>> Reported-by: Shannon Zhao <zhaoshenglong@xxxxxxxxxx> >>>>>> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> >>>>>> --- >>>>>> virt/kvm/arm/vgic.c | 4 ++-- >>>>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>>>> >>>>>> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c >>>>>> index b6fab0f..8629678 100644 >>>>>> --- a/virt/kvm/arm/vgic.c >>>>>> +++ b/virt/kvm/arm/vgic.c >>>>>> @@ -816,7 +816,7 @@ static bool read_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu, >>>>>> { >>>>>> struct vgic_dist *dist = &vcpu->kvm->arch.vgic; >>>>>> int sgi; >>>>>> - int min_sgi = (offset & ~0x3) * 4; >>>>>> + int min_sgi = (offset & ~0x3); >>>>>> int max_sgi = min_sgi + 3; >>>>>> int vcpu_id = vcpu->vcpu_id; >>>>>> u32 reg = 0; >>>>>> @@ -837,7 +837,7 @@ static bool write_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu, >>>>>> { >>>>>> struct vgic_dist *dist = &vcpu->kvm->arch.vgic; >>>>>> int sgi; >>>>>> - int min_sgi = (offset & ~0x3) * 4; >>>>>> + int min_sgi = (offset & ~0x3); >>>>>> int max_sgi = min_sgi + 3; >>>>>> int vcpu_id = vcpu->vcpu_id; >>>>>> u32 reg; >>>>>> >>>>> Hi Christoffer, >>>>> >>>>> I have test this patch for a few hours. The kfree() bug doesn't appear again. >>>>> But I come to another problem as followed. >>>>> The test is that start 2 VMs, sleep 10 and do pkill qemu. >>>>> >>>>> qemu-system-aar[1207]: unhandled level 1 permission fault (11) at 0xffffc01ed6c200, esr 0x9200000d >>>>> pgd = ffffffc012986000 >>>>> [ffffc01ed6c200] *pgd=0000000000000000, *pud=0000000000000000 >>>>> >>>>> CPU: 1 PID: 1207 Comm: qemu-system-aar Not tainted 3.17.0-rc4+ #1 >>>>> task: ffffffc87b072900 ti: ffffffc0129e0000 task.ti: ffffffc0129e0000 >>>>> PC is at 0x4181a0 >>>>> LR is at 0x41826c >>>>> pc : [<00000000004181a0>] lr : [<000000000041826c>] pstate: 80000000 >>>>> sp : 0000007fcd38ace0 >>>>> x29: 0000007fcd38ace0 x28: 0000000000000000 >>>>> x27: 0000000000000000 x26: 0000000000000000 >>>>> x25: 0000000000000000 x24: 0000000000000000 >>>>> x23: 0000000000000000 x22: 0000000000000000 >>>>> x21: 0000000000000000 x20: 0000000000000000 >>>>> x19: 0000007fcd38b070 x18: 0000007fcd38ab10 >>>>> x17: 0000007f9bb14480 x16: 00000000009f2370 >>>>> x15: ffffffffffffffff x14: 0000000000000000 >>>>> x13: 0000000000000000 x12: 0000000000000268 >>>>> x11: 00000000115e5520 x10: 0101010101010101 >>>>> x9 : 0000000000000004 x8 : 0000000000ac7a78 >>>>> x7 : 0000000000000000 x6 : 000000000000003f >>>>> x5 : 0000000000000040 x4 : 0000000000000000 >>>>> x3 : 0000000000000030 x2 : 0000000000000001 >>>>> x1 : ffffffc01ed6c200 x0 : ffffffc01ed6c200 >>>>> >>>> Hmmm, I just ran a similar loop with a number of tests in the VM for a >>>> few hours and I didn't see this error. >>> Yeah, it really need to run longer. >>> After running about one hour this problem first appears and after running >>> about 4 hours it second appears. >>>> >>>> In any case, this patch should still be merged, but we should try to >>>> reproduce your setup. >>> Your patch really solves the kfree() bug. I'll add tested-by line. >>>> >>>> What is your command line, exact QEMU version, the file system you use, >>>> and the guest kernel you are running? >>> My test script is as followed. QEMU version is v2.1.0 release. >>> The fs is linaro-image-lamp-genericarmv8-20140727-701.rootfs.tar.gz. >>> Host kernel is based on marc's branch "kvmtool-vgic-dyn" with your patch >>> "Fix set_clear_sgi_pend_reg offset". >>> Guest kernel is 3.16 release. >>> >>> while true >>> do >>> qemu-system-aarch64 \ >>> -enable-kvm -smp 4 \ >>> -kernel Image \ >>> -m 512 -machine virt,kernel_irqchip=on \ >>> -initrd guestfs.cpio.gz \ >>> -cpu host \ >>> -chardev pty,id=pty0,mux=on -monitor chardev:pty0 \ >>> -serial chardev:pty0 -daemonize \ >>> -vnc 0.0.0.0:0 \ >>> -append "rdinit=/sbin/init console=ttyAMA0 mem=512M root=/dev/ram earlyprintk=pl011,0x9000000 rw" & >>> >>> qemu-system-aarch64 \ >>> -enable-kvm -smp 4 \ >>> -kernel Image \ >>> -m 512 -machine virt,kernel_irqchip=on \ >>> -initrd guestfs.cpio.gz \ >>> -cpu host \ >>> -chardev pty,id=pty0,mux=on -monitor chardev:pty0 \ >>> -serial chardev:pty0 -daemonize \ >>> -vnc 0.0.0.0:1 \ >>> -append "rdinit=/sbin/init console=ttyAMA0 mem=512M root=/dev/ram earlyprintk=pl011,0x9000000 rw" & >>> sleep 5 >>> pkill qemu >> >> ok, I'll try to reproduce. >> > With kvmarm/queue as both host and guest and otherwise not using vnc but > nographic and a serial output, I've now been running this for 5 hours > straight without any issues. That's 1131 runs (2x number of guests > booted) and counting without seeing this... > I have ran the test with kvmarm/queue as both host and guest using nographic and a serial output. The problem appears. My environment info: kvmarm/queue: commit f003101732065c7e61a4d5394cfc69b01b0bb157 arm/arm64: KVM: Fix VTTBR_BADDR_MASK and pgd alloc qemu: commit 541bbb07eb197a870661ed702ae1f15c7d46aea6 Update version for v2.1.0 release fs: guest: linaro-image-minimal-genericarmv8-20140727-701.rootfs.tar.gz host: use above minimal fs and add some libs from linaro-image-lamp-genericarmv8-20140727-701.rootfs.tar.gz Once this problem appeared, it appears every time when start a vm. The problem info is always same: qemu-system-aar[1207]: unhandled level 1 permission fault (11) at 0xffffc01ed6c200, esr 0x9200000d > -Christoffer > > . > -- Shannon -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
