pm24.git/virt, branch v4.3-rc6

KVM: disable halt_poll_ns as default for s390x

2015-09-25T08:31:30Z

We observed some performance degradation on s390x with dynamic halt polling. Until we can provide a proper fix, let's enable halt_poll_ns as default only for supported architectures. Architectures are now free to set their own halt_poll_ns default value. Signed-off-by: David Hildenbrand Signed-off-by: Paolo Bonzini

Merge tag 'kvm-arm-for-4.3-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

2015-09-17T14:51:59Z

Second set of KVM/ARM changes for 4.3-rc2 - Workaround for a Cortex-A57 erratum - Bug fix for the debugging infrastructure - Fix for 32bit guests with more than 4GB of address space on a 32bit host - A number of fixes for the (unusual) case when we don't use the in-kernel GIC emulation - Removal of ThumbEE handling on arm64, since these have been dropped from the architecture before anyone actually ever built a CPU - Remove the KVM_ARM_MAX_VCPUS limitation which has become fairly pointless

arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS'

2015-09-17T12:13:27Z

This patch removes config option of KVM_ARM_MAX_VCPUS, and like other ARCHs, just choose the maximum allowed value from hardware, and follows the reasons: 1) from distribution view, the option has to be defined as the max allowed value because it need to meet all kinds of virtulization applications and need to support most of SoCs; 2) using a bigger value doesn't introduce extra memory consumption, and the help text in Kconfig isn't accurate because kvm_vpu structure isn't allocated until request of creating VCPU is sent from QEMU; 3) the main effect is that the field of vcpus[] in 'struct kvm' becomes a bit bigger(sizeof(void *) per vcpu) and need more cache lines to hold the structure, but 'struct kvm' is one generic struct, and it has worked well on other ARCHs already in this way. Also, the world switch frequecy is often low, for example, it is ~2000 when running kernel building load in VM from APM xgene KVM host, so the effect is very small, and the difference can't be observed in my test at all. Cc: Dann Frazier Signed-off-by: Ming Lei Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier

KVM: add halt_attempted_poll to VCPU stats

2015-09-16T10:17:00Z

This new statistic can help diagnosing VCPUs that, for any reason, trigger bad behavior of halt_poll_ns autotuning. For example, say halt_poll_ns = 480000, and wakeups are spaced exactly like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes 10+20+40+80+160+320+480 = 1110 microseconds out of every 479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then is consuming about 30% more CPU than it would use without polling. This would show as an abnormally high number of attempted polling compared to the successful polls. Acked-by: Christian Borntraeger Signed-off-by: Paolo Bonzini

kvm: fix zero length mmio searching

2015-09-15T14:59:46Z

Currently, if we had a zero length mmio eventfd assigned on KVM_MMIO_BUS. It will never be found by kvm_io_bus_cmp() since it always compares the kvm_io_range() with the length that guest wrote. This will cause e.g for vhost, kick will be trapped by qemu userspace instead of vhost. Fixing this by using zero length if an iodevice is zero length. Cc: stable@vger.kernel.org Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini

kvm: fix double free for fast mmio eventfd

2015-09-15T14:59:31Z

We register wildcard mmio eventfd on two buses, once for KVM_MMIO_BUS and once on KVM_FAST_MMIO_BUS but with a single iodev instance. This will lead to an issue: kvm_io_bus_destroy() knows nothing about the devices on two buses pointing to a single dev. Which will lead to double free[1] during exit. Fix this by allocating two instances of iodevs then registering one on KVM_MMIO_BUS and another on KVM_FAST_MMIO_BUS. CPU: 1 PID: 2894 Comm: qemu-system-x86 Not tainted 3.19.0-26-generic #28-Ubuntu Hardware name: LENOVO 2356BG6/2356BG6, BIOS G7ET96WW (2.56 ) 09/12/2013 task: ffff88009ae0c4b0 ti: ffff88020e7f0000 task.ti: ffff88020e7f0000 RIP: 0010:[] [] ioeventfd_release+0x28/0x60 [kvm] RSP: 0018:ffff88020e7f3bc8 EFLAGS: 00010292 RAX: dead000000200200 RBX: ffff8801ec19c900 RCX: 000000018200016d RDX: ffff8801ec19cf80 RSI: ffffea0008bf1d40 RDI: ffff8801ec19c900 RBP: ffff88020e7f3bd8 R08: 000000002fc75a01 R09: 000000018200016d R10: ffffffffc07df6ae R11: ffff88022fc75a98 R12: ffff88021e7cc000 R13: ffff88021e7cca48 R14: ffff88021e7cca50 R15: ffff8801ec19c880 FS: 00007fc1ee3e6700(0000) GS:ffff88023e240000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8f389d8000 CR3: 000000023dc13000 CR4: 00000000001427e0 Stack: ffff88021e7cc000 0000000000000000 ffff88020e7f3be8 ffffffffc07e2622 ffff88020e7f3c38 ffffffffc07df69a ffff880232524160 ffff88020e792d80 0000000000000000 ffff880219b78c00 0000000000000008 ffff8802321686a8 Call Trace: [] ioeventfd_destructor+0x12/0x20 [kvm] [] kvm_put_kvm+0xca/0x210 [kvm] [] kvm_vcpu_release+0x18/0x20 [kvm] [] __fput+0xe7/0x250 [] ____fput+0xe/0x10 [] task_work_run+0xd4/0xf0 [] do_exit+0x368/0xa50 [] ? recalc_sigpending+0x1f/0x60 [] do_group_exit+0x45/0xb0 [] get_signal+0x291/0x750 [] do_signal+0x28/0xab0 [] ? do_futex+0xdb/0x5d0 [] ? __wake_up_locked_key+0x18/0x20 [] ? SyS_futex+0x76/0x170 [] do_notify_resume+0x69/0xb0 [] int_signal+0x12/0x17 Code: 5d c3 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 8b 7f 20 e8 06 d6 a5 c0 48 8b 43 08 48 8b 13 48 89 df 48 89 42 08 <48> 89 10 48 b8 00 01 10 00 00 RIP [] ioeventfd_release+0x28/0x60 [kvm] RSP Cc: stable@vger.kernel.org Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini

kvm: factor out core eventfd assign/deassign logic

2015-09-15T14:58:47Z

This patch factors out core eventfd assign/deassign logic and leaves the argument checking and bus index selection to callers. Cc: stable@vger.kernel.org Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini

kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd

2015-09-15T14:58:27Z

We only want zero length mmio eventfd to be registered on KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to make sure this. Cc: stable@vger.kernel.org Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini

KVM: make the declaration of functions within 80 characters

2015-09-14T16:43:19Z

After 'commit 0b8ba4a2b658 ("KVM: fix checkpatch.pl errors in kvm/coalesced_mmio.h")', the declaration of the two function will exceed 80 characters. This patch reduces the TAPs to make each line in 80 characters. Signed-off-by: Wei Yang Signed-off-by: Paolo Bonzini

Merge tag 'kvm-arm-for-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

2015-09-14T15:07:35Z

KVM/ARM changes for 4.3-rc2 - Fix timer interrupt injection after the rework that went in during the merge window - Reset the timer to zero on reboot - Make sure the TCR_EL2 RES1 bits are really set to 1 - Fix a PSCI affinity bug for non-existing vcpus