- Jan 31, 2018
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Vitaly Kuznetsov authored
I was investigating an issue with seabios >= 1.10 which stopped working for nested KVM on Hyper-V. The problem appears to be in handle_ept_violation() function: when we do fast mmio we need to skip the instruction so we do kvm_skip_emulated_instruction(). This, however, depends on VM_EXIT_INSTRUCTION_LEN field being set correctly in VMCS. However, this is not the case. Intel's manual doesn't mandate VM_EXIT_INSTRUCTION_LEN to be set when EPT MISCONFIG occurs. While on real hardware it was observed to be set, some hypervisors follow the spec and don't set it; we end up advancing IP with some random value. I checked with Microsoft and they confirmed they don't fill VM_EXIT_INSTRUCTION_LEN on EPT MISCONFIG. Fix the issue by doing instruction skip through emulator when running nested. Fixes: 68c3b4d1 Suggested-by:
Radim Krčmář <rkrcmar@redhat.com> Suggested-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by:
Michael S. Tsirkin <mst@redhat.com> Signed-off-by:
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Masatake YAMATO authored
All d-entries for vcpu have the same, "anon_inode:kvm-vcpu". That means it is impossible to know the mapping between fds for vcpu and vcpu from userland. # LC_ALL=C ls -l /proc/617/fd | grep vcpu lrwx------. 1 qemu qemu 64 Jan 7 16:50 18 -> anon_inode:kvm-vcpu lrwx------. 1 qemu qemu 64 Jan 7 16:50 19 -> anon_inode:kvm-vcpu It is also impossible to know the mapping between vma for kvm_run structure and vcpu from userland. # LC_ALL=C grep vcpu /proc/617/maps 7f9d842d0000-7f9d842d3000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu 7f9d842d3000-7f9d842d6000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu This change adds vcpu id to d-entries for vcpu. With this change you can get the following output: # LC_ALL=C ls -l /proc/617/fd | grep vcpu lrwx------. 1 qemu qemu 64 Jan 7 16:50 18 -> anon_inode:kvm-vcpu:0 lrwx------. 1 qemu qemu 64 Jan 7 16:50 19 -> anon_inode:kvm-vcpu:1 # LC_ALL=C grep vcpu /proc/617/maps 7f9d842d0000-7f9d842d3000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu:0 7f9d842d3000-7f9d842d6000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu:1 With the mappings known from the output, a tool like strace can report more details of qemu-kvm process activities. Here is the strace output of my local prototype: # ./strace -KK -f -p 617 2>&1 | grep 'KVM_RUN\| K' ... [pid 664] ioctl(18, KVM_RUN, 0) = 0 (KVM_EXIT_MMIO) K ready_for_interrupt_injection=1, if_flag=0, flags=0, cr8=0000000000000000, apic_base=0x000000fee00d00 K phys_addr=0, len=1634035803, [33, 0, 0, 0, 0, 0, 0, 0], is_write=112 [pid 664] ioctl(18, KVM_RUN, 0) = 0 (KVM_EXIT_MMIO) K ready_for_interrupt_injection=1, if_flag=1, flags=0, cr8=0000000000000000, apic_base=0x000000fee00d00 K phys_addr=0, len=1634035803, [33, 0, 0, 0, 0, 0, 0, 0], is_write=112 ... Signed-off-by:Masatake YAMATO <yamato@redhat.com> Acked-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
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KarimAllah Ahmed authored
For EPT-violations that are triggered by a read, the pages are also mapped with write permissions (if their memory region is also writable). That would avoid getting yet another fault on the same page when a write occurs. This optimization only happens when you have a "struct page" backing the memory region. So also enable it for memory regions that do not have a "struct page". Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by:
KarimAllah Ahmed <karahmed@amazon.de> Reviewed-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarmRadim Krčmář authored
KVM/ARM Changes for v4.16 The changes for this version include icache invalidation optimizations (improving VM startup time), support for forwarded level-triggered interrupts (improved performance for timers and passthrough platform devices), a small fix for power-management notifiers, and some cosmetic changes.
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linuxRadim Krčmář authored
KVM: s390: update maintainers
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Christoffer Dall authored
When I introduced a static key to avoid work in the critical path for userspace irqchips which is very rarely used, I accidentally messed up my logic and used && where I should have used ||, because the point was to short-circuit the evaluation in case userspace irqchips weren't even in use. This fixes an issue when running in-kernel irqchip VMs alongside userspace irqchip VMs. Acked-by:
Marc Zyngier <marc.zyngier@arm.com> Fixes: c44c232ee2d3 ("KVM: arm/arm64: Avoid work when userspace iqchips are not used") Signed-off-by:
Christoffer Dall <christoffer.dall@linaro.org>
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Christoffer Dall authored
We were not decrementing the static key count in the right location. kvm_arch_vcpu_destroy() is only called to clean up after a failed VCPU create attempt, whereas kvm_arch_vcpu_free() is called on teardown of the VM as well. Move the static key decrement call to kvm_arch_vcpu_free(). Acked-by:
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Christoffer Dall authored
After the recently introduced support for level-triggered mapped interrupt, I accidentally left the VCPU thread busily going back and forward between the guest and the hypervisor whenever the guest was blocking, because I would always incorrectly report that a timer interrupt was pending. This is because the timer->irq.level field is not valid for mapped interrupts, where we offload the level state to the hardware, and as a result this field is always true. Luckily the problem can be relatively easily solved by not checking the cached signal state of either timer in kvm_timer_should_fire() but instead compute the timer state on the fly, which we do already if the cached signal state wasn't high. In fact, the only reason for checking the cached signal state was a tiny optimization which would only be potentially faster when the polling loop detects a pending timer interrupt, which is quite unlikely. Instead of duplicating the logic from kvm_arch_timer_handler(), we enlighten kvm_timer_should_fire() to report something valid when the timer state is loaded onto the hardware. We can then call this from kvm_arch_timer_handler() as well and avoid the call to __timer_snapshot_state() in kvm_arch_timer_get_input_level(). Reported-by:
Tomasz Nowicki <tn@semihalf.com> Tested-by:
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Cornelia Huck authored
As I have neither too much time nor access to the architecture documentation anymore, let's switch my status from maintainer to reviewer. Janosch will step in as second maintainer. Acked-by:
Janosch Frank <frankja@linux.vnet.ibm.com> Acked-by:
Cornelia Huck <cohuck@redhat.com>
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Cornelia Huck authored
Acked-by:
Halil Pasic <pasic@linux.vnet.ibm.com> Acked-by:
Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Signed-off-by:
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Cornelia Huck authored
Acked-by:
David Hildenbrand <david@redhat.com> Signed-off-by:
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- Jan 30, 2018
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linuxRadim Krčmář authored
KVM: s390: Fixes and features for 4.16 part 2 - exitless interrupts for emulated devices (Michael Mueller) - cleanup of cpuflag handling (David Hildenbrand) - kvm stat counter improvements (Christian Borntraeger) - vsie improvements (David Hildenbrand) - mm cleanup (Janosch Frank)
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- Jan 26, 2018
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Michael Mueller authored
The patch modifies the previously defined GISA data structure to be able to store two GISA formats, format-0 and format-1. Additionally, it verifies the availability of the GISA format facility and enables the use of a format-1 GISA in the SIE control block accordingly. A format-1 can do everything that format-0 can and we will need it for real HW passthrough. As there are systems with only format-0 we keep both variants. Signed-off-by:
Michael Mueller <mimu@linux.vnet.ibm.com> Reviewed-by:
Pierre Morel <pmorel@linux.vnet.ibm.com> Reviewed-by:
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Michael Mueller authored
The GISA format facility is required by the host to be able to process a format-1 GISA. If not available, the used GISA format will be format-0. All format-1 related extension will not be available in this case. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
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Michael Mueller authored
If the AIV facility is available, a GISA will be used to manage emulated adapter interrupts. Signed-off-by:
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Michael Mueller authored
The function returns a pending I/O interrupt with the highest priority defined by its ISC. Together with AIV activation, pending adapter interrupts are managed by the GISA IPM. Thus kvm_s390_get_io_int() needs to inspect the IPM as well when the interrupt with the highest priority has to be identified. In case classic and adapter interrupts with the same ISC are pending, the classic interrupt will be returned first. Signed-off-by:
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Michael Mueller authored
Pending interrupts marked in the GISA IPM are required to become part of the answer of ioctl KVM_DEV_FLIC_GET_ALL_IRQS. The ioctl KVM_DEV_FLIC_ENQUEUE is already capable to enqueue adapter interrupts when a GISA is present. With ioctl KVM_DEV_FLIC_CLEAR_IRQS the GISA IPM wil be cleared now as well. Signed-off-by:
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Michael Mueller authored
The function isc_to_int_word() allows the generation of interruption words for adapter interrupts. Signed-off-by:
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Michael Mueller authored
The adapter interruption virtualization (AIV) facility is an optional facility that comes with functionality expected to increase the performance of adapter interrupt handling for both emulated and passed-through adapter interrupts. With AIV, adapter interrupts can be delivered to the guest without exiting SIE. This patch provides some preparations for using AIV for emulated adapter interrupts (including virtio) if it's available. When using AIV, the interrupts are delivered at the so called GISA by setting the bit corresponding to its Interruption Subclass (ISC) in the Interruption Pending Mask (IPM) instead of inserting a node into the floating interrupt list. To keep the change reasonably small, the handling of this new state is deferred in get_all_floating_irqs and handle_tpi. This patch concentrates on the code handling enqueuement of emulated adapter interrupts, and their delivery to the guest. Note that care is still required for adapter interrupts using AIV, because there is no guarantee that AIV is going to deliver the adapter interrupts pending at the GISA (consider all vcpus idle). When delivering GISA adapter interrupts by the host (usual mechanism) special attention is required to honor interrupt priorities. Empirical results show that the time window between making an interrupt pending at the GISA and doing kvm_s390_deliver_pending_interrupts is sufficient for a guest with at least moderate cpu activity to get adapter interrupts delivered within the SIE, and potentially save some SIE exits (if not other deliverable interrupts). The code will be activated with a follow-up patch. Signed-off-by:
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Michael Mueller authored
The patch adds an indication for the presence Adapter Interruption Virtualization facility (AIV) of the general channel subsystem characteristics. Signed-off-by:
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Michael Mueller authored
The patch implements routines to access the GISA to test and modify its Interruption Pending Mask (IPM) from the host side. Signed-off-by:
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Jens Freimann authored
This patch adds a MSB0 bit numbering version of test_and_clear_bit(). Signed-off-by:
Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by:
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Michael Mueller authored
In preperation to support pass-through adapter interrupts, the Guest Interruption State Area (GISA) and the Adapter Interruption Virtualization (AIV) features will be introduced here. This patch introduces format-0 GISA (that is defines the struct describing the GISA, allocates storage for it, and introduces fields for the GISA address in kvm_s390_sie_block and kvm_s390_vsie). As the GISA requires storage below 2GB, it is put in sie_page2, which is already allocated in ZONE_DMA. In addition, The GISA requires alignment to its integral boundary. This is already naturally aligned via the padding in the sie_page2. Signed-off-by:
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Michael Mueller authored
This patch prepares a simplification of bit operations between the irq pending mask for emulated interrupts and the Interruption Pending Mask (IPM) which is part of the Guest Interruption State Area (GISA), a feature that allows interrupt delivery to guests by means of the SIE instruction. Without that change, a bit-wise *or* operation on parts of these two masks would either require a look-up table of size 256 bytes to map the IPM to the emulated irq pending mask bit orientation (all bits mirrored at half byte) or a sequence of up to 8 condidional branches to perform tests of single bit positions. Both options are to be rejected either by performance or space utilization reasons. Beyond that this change will be transparent. Signed-off-by:
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- Jan 24, 2018
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David Hildenbrand authored
Use it just like kvm_s390_set_cpuflags() and kvm_s390_clear_cpuflags(). Signed-off-by:
Thomas Huth <thuth@redhat.com> Reviewed-by:
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David Hildenbrand authored
Use it just like kvm_s390_set_cpuflags(). Suggested-by:
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David Hildenbrand authored
Use it in all places where we set cpuflags. Signed-off-by:
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David Hildenbrand authored
No need to make this function special. Move it to a header right away. Signed-off-by:
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Christian Borntraeger authored
The overall instruction counter is larger than the sum of the single counters. We should try to catch all instruction handlers to make this match the summary counter. Let us add sck,tb,sske,iske,rrbe,tb,tpi,tsch,lpsw,pswe.... and remove other unused ones. Signed-off-by:
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Christian Borntraeger authored
Make the diagnose counters also appear as instruction counters. Signed-off-by:
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David Hildenbrand authored
We never call it with anything but PROT_READ. This is a left over from an old prototype. For creation of shadow page tables, we always only have to protect the original table in guest memory from write accesses, so we can properly invalidate the shadow on writes. Other protections are not needed. Signed-off-by:
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David Hildenbrand authored
This way, the values cannot change, even if another VCPU might try to mess with the nested SCB currently getting executed by another VCPU. We now always use the same gpa for pinning and unpinning a page (for unpinning, it is only relevant to mark the guest page dirty for migration). Signed-off-by:
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David Hildenbrand authored
Another VCPU might try to modify the SCB while we are creating the shadow SCB. In general this is no problem - unless the compiler decides to not load values once, but e.g. twice. For us, this is only relevant when checking/working with such values. E.g. the prefix value, the mso, state of transactional execution and addresses of satellite blocks. E.g. if we blindly forward values (e.g. general purpose registers or execution controls after masking), we don't care. Leaving unpin_blocks() untouched for now, will handle it separately. The worst thing right now that I can see would be a missed prefix un/remap (mso, prefix, tx) or using wrong guest addresses. Nothing critical, but let's try to avoid unpredictable behavior. Signed-off-by:
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- Jan 23, 2018
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Luis de Bethencourt authored
The trailing semicolon is an empty statement that does no operation. Removing it since it doesn't do anything. Signed-off-by:
Luis de Bethencourt <luisbg@kernel.org> Signed-off-by:
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James Morse authored
cpu_pm_enter() calls the pm notifier chain with CPU_PM_ENTER, then if there is a failure: CPU_PM_ENTER_FAILED. When KVM receives CPU_PM_ENTER it calls cpu_hyp_reset() which will return us to the hyp-stub. If we subsequently get a CPU_PM_ENTER_FAILED, KVM does nothing, leaving the CPU running with the hyp-stub, at odds with kvm_arm_hardware_enabled. Add CPU_PM_ENTER_FAILED as a fallthrough for CPU_PM_EXIT, this reloads KVM based on kvm_arm_hardware_enabled. This is safe even if CPU_PM_ENTER never gets as far as KVM, as cpu_hyp_reinit() calls cpu_hyp_reset() to make sure the hyp-stub is loaded before reloading KVM. Fixes: 67f69197 ("arm64: kvm: allows kvm cpu hotplug") Cc: <stable@vger.kernel.org> # v4.7+ CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by:
James Morse <james.morse@arm.com> Signed-off-by:
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Janosch Frank authored
It seems it hasn't even been used before the last cleanup and was overlooked. Signed-off-by:
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- Jan 17, 2018
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Christoffer Dall authored
Add an extra temporary register parameter to uaccess_ttbr0_disable which is about to be required for arm64 PAN support. This patch doesn't introduce any functional change but ensures that the kernel compiles once the KVM/ARM tree is merged with the arm64 tree by ensuring a trivially mergable conflict with commit 6b88a32c ("arm64: kpti: Fix the interaction between ASID switching and software PAN"). Cc: Will Deacon <will.deacon@arm.com> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Acked-by:
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- Jan 16, 2018
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Paolo Bonzini authored
Remove duplicate expression in nested_vmx_prepare_msr_bitmap, and make the register names clearer in hardware_setup. Suggested-by:
Jim Mattson <jmattson@google.com> Reviewed-by:
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Paolo Bonzini authored
The bulk of the MSR bitmap is either immutable, or can be copied from the L1 bitmap. By initializing it at VMXON time, and copying the mutable parts one long at a time on vmentry (rather than one bit), about 4000 clock cycles (30%) can be saved on a nested VMLAUNCH/VMRESUME. The resulting for loop only has four iterations, so it is cheap enough to reinitialize the MSR write bitmaps on every iteration, and it makes the code simpler. Suggested-by:
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Paolo Bonzini authored
The APICv-enabled MSR bitmap is a superset of the APICv-disabled bitmap. Make that obvious in vmx_disable_intercept_msr_x2apic. Signed-off-by:
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