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* [S390] kvm: extension capability for new address space layoutChristian Borntraeger2011-09-201-0/+1
| | | | | | | | | | | | | | | | | | 598841ca9919d008b520114d8a4378c4ce4e40a1 ([S390] use gmap address spaces for kvm guest images) changed kvm on s390 to use a separate address space for kvm guests. We can now put KVM guests anywhere in the user address mode with a size up to 8PB - as long as the memory is 1MB-aligned. This change was done without KVM extension capability bit. The change was added after 3.0, but we still have a chance to add a feature bit before 3.1 (keeping the releases in a sane state). We use number 71 to avoid collisions with other pending kvm patches as requested by Alexander Graf. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Avi Kivity <avi@redhat.com> Cc: Alexander Graf <agraf@suse.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guestsPaul Mackerras2011-07-121-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds infrastructure which will be needed to allow book3s_hv KVM to run on older POWER processors, including PPC970, which don't support the Virtual Real Mode Area (VRMA) facility, but only the Real Mode Offset (RMO) facility. These processors require a physically contiguous, aligned area of memory for each guest. When the guest does an access in real mode (MMU off), the address is compared against a limit value, and if it is lower, the address is ORed with an offset value (from the Real Mode Offset Register (RMOR)) and the result becomes the real address for the access. The size of the RMA has to be one of a set of supported values, which usually includes 64MB, 128MB, 256MB and some larger powers of 2. Since we are unlikely to be able to allocate 64MB or more of physically contiguous memory after the kernel has been running for a while, we allocate a pool of RMAs at boot time using the bootmem allocator. The size and number of the RMAs can be set using the kvm_rma_size=xx and kvm_rma_count=xx kernel command line options. KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability of the pool of preallocated RMAs. The capability value is 1 if the processor can use an RMA but doesn't require one (because it supports the VRMA facility), or 2 if the processor requires an RMA for each guest. This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the pool and returns a file descriptor which can be used to map the RMA. It also returns the size of the RMA in the argument structure. Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION ioctl calls from userspace. To cope with this, we now preallocate the kvm->arch.ram_pginfo array when the VM is created with a size sufficient for up to 64GB of guest memory. Subsequently we will get rid of this array and use memory associated with each memslot instead. This moves most of the code that translates the user addresses into host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level to kvmppc_core_prepare_memory_region. Also, instead of having to look up the VMA for each page in order to check the page size, we now check that the pages we get are compound pages of 16MB. However, if we are adding memory that is mapped to an RMA, we don't bother with calling get_user_pages_fast and instead just offset from the base pfn for the RMA. Typically the RMA gets added after vcpus are created, which makes it inconvenient to have the LPCR (logical partition control register) value in the vcpu->arch struct, since the LPCR controls whether the processor uses RMA or VRMA for the guest. This moves the LPCR value into the kvm->arch struct and arranges for the MER (mediated external request) bit, which is the only bit that varies between vcpus, to be set in assembly code when going into the guest if there is a pending external interrupt request. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
* KVM: PPC: Allow book3s_hv guests to use SMT processor modesPaul Mackerras2011-07-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
* KVM: PPC: Accelerate H_PUT_TCE by implementing it in real modeDavid Gibson2011-07-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | This improves I/O performance for guests using the PAPR paravirtualization interface by making the H_PUT_TCE hcall faster, by implementing it in real mode. H_PUT_TCE is used for updating virtual IOMMU tables, and is used both for virtual I/O and for real I/O in the PAPR interface. Since this moves the IOMMU tables into the kernel, we define a new KVM_CREATE_SPAPR_TCE ioctl to allow qemu to create the tables. The ioctl returns a file descriptor which can be used to mmap the newly created table. The qemu driver models use them in the same way as userspace managed tables, but they can be updated directly by the guest with a real-mode H_PUT_TCE implementation, reducing the number of host/guest context switches during guest IO. There are certain circumstances where it is useful for userland qemu to write to the TCE table even if the kernel H_PUT_TCE path is used most of the time. Specifically, allowing this will avoid awkwardness when we need to reset the table. More importantly, we will in the future need to write the table in order to restore its state after a checkpoint resume or migration. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
* KVM: PPC: Add support for Book3S processors in hypervisor modePaul Mackerras2011-07-121-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
* KVM: Clarify KVM_ASSIGN_PCI_DEVICE documentationJan Kiszka2011-07-121-7/+1
| | | | | | | | Neither host_irq nor the guest_msi struct are used anymore today. Tag the former, drop the latter to avoid confusion. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PPC: booke: add sregs supportScott Wood2011-05-221-0/+1
| | | | | Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
* KVM: X86: Implement userspace interface to set virtual_tsc_khzJoerg Roedel2011-05-111-0/+5
| | | | | | | | | | This patch implements two new vm-ioctls to get and set the virtual_tsc_khz if the machine supports tsc-scaling. Setting the tsc-frequency is only possible before userspace creates any vcpu. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Add PV MSR to enable asynchronous page faults delivery.Gleb Natapov2011-01-121-0/+1
| | | | | | | | Guest enables async PF vcpu functionality using this MSR. Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: PPC: Expose level based interrupt capAlexander Graf2010-10-241-0/+1
| | | | | | | Now that we have all the level interrupt magic in place, let's expose the capability to user space, so it can make use of it! Signed-off-by: Alexander Graf <agraf@suse.de>
* KVM: PPC: Add get_pvinfo interface to query hypercall instructionsAlexander Graf2010-10-241-0/+11
| | | | | | | | | | | | | | | We need to tell the guest the opcodes that make up a hypercall through interfaces that are controlled by userspace. So we need to add a call for userspace to allow it to query those opcodes so it can pass them on. This is required because the hypercall opcodes can change based on the hypervisor conditions. If we're running in hardware accelerated hypervisor mode, a hypercall looks different from when we're running without hardware acceleration. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Remove memory alias supportAvi Kivity2010-08-011-0/+1
| | | | | | | As advertised in feature-removal-schedule.txt. Equivalent support is provided by overlapping memory regions. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: XSAVE/XRSTOR live migration supportSheng Yang2010-08-011-0/+12
| | | | | | | This patch enable save/restore of xsave state. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: PPC: Add OSI hypercall interfaceAlexander Graf2010-05-171-0/+6
| | | | | | | | | | | | | MOL uses its own hypercall interface to call back into userspace when the guest wants to do something. So let's implement that as an exit reason, specify it with a CAP and only really use it when userspace wants us to. The only user of it so far is MOL. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Add support for enabling capabilities per-vcpuAlexander Graf2010-05-171-0/+11
| | | | | | | | | | | | | | Some times we don't want all capabilities to be available to all our vcpus. One example for that is the OSI interface, implemented in the next patch. In order to have a generic mechanism in how to enable capabilities individually, this patch introduces a new ioctl that can be used for this purpose. That way features we don't want in all guests or userspace configurations can just not be enabled and we're good. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PPC: Allow userspace to unset the IRQ lineAlexander Graf2010-05-171-0/+1
| | | | | | | | | | | | | | | Userspace can tell us that it wants to trigger an interrupt. But so far it can't tell us that it wants to stop triggering one. So let's interpret the parameter to the ioctl that we have anyways to tell us if we want to raise or lower the interrupt line. Signed-off-by: Alexander Graf <agraf@suse.de> v2 -> v3: - Add CAP for unset irq Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: Add support for saving&restoring debug registersJan Kiszka2010-04-251-0/+6
| | | | | | | | So far user space was not able to save and restore debug registers for migration or after reset. Plug this hole. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: Save&restore interrupt shadow maskJan Kiszka2010-04-251-0/+1
| | | | | | | | | | | | | The interrupt shadow created by STI or MOV-SS-like operations is part of the VCPU state and must be preserved across migration. Transfer it in the spare padding field of kvm_vcpu_events.interrupt. As a side effect we now have to make vmx_set_interrupt_shadow robust against both shadow types being set. Give MOV SS a higher priority and skip STI in that case to avoid that VMX throws a fault on next entry. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PPC: Add capability for paired singlesAlexander Graf2010-04-251-0/+1
| | | | | | | | We need to tell userspace that we can emulate paired single instructions. So let's add a capability export. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: Add KVM_CAP_X86_ROBUST_SINGLESTEPJan Kiszka2010-03-011-0/+1
| | | | | | | | | | This marks the guest single-step API improvement of 94fe45da and 91586a3b with a capability flag to allow reliable detection by user space. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: stable@kernel.org (2.6.33) Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: enable PCI multiple-segments for pass-through deviceZhai, Edwin2010-03-011-1/+3
| | | | | | | | | Enable optional parameter (default 0) - PCI segment (or domain) besides BDF, when assigning PCI device to guest. Signed-off-by: Zhai Edwin <edwin.zhai@intel.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Implement NotifyLongSpinWait HYPER-V hypercallGleb Natapov2010-03-011-0/+1
| | | | | | | | | Windows issues this hypercall after guest was spinning on a spinlock for too many iterations. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Add HYPER-V apic access MSRsGleb Natapov2010-03-011-0/+1
| | | | | | | | | Implement HYPER-V apic MSRs. Spec defines three MSRs that speed-up access to EOI/TPR/ICR apic registers for PV guests. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Implement bare minimum of HYPER-V MSRsGleb Natapov2010-03-011-0/+1
| | | | | | | | | | | Minimum HYPER-V implementation should have GUEST_OS_ID, HYPERCALL and VP_INDEX MSRs. [avi: fix build on i386] Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU updateMarcelo Tosatti2010-03-011-1/+1
| | | | | | | | | | Use two steps for memslot deletion: mark the slot invalid (which stops instantiation of new shadow pages for that slot, but allows destruction), then instantiate the new empty slot. Also simplifies kvm_handle_hva locking. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* Merge commit 'origin/master' into nextBenjamin Herrenschmidt2009-12-091-118/+156
|\ | | | | | | | | Conflicts: include/linux/kvm.h
| * KVM: s390: Make psw available on all exits, not just a subsetCarsten Otte2009-12-031-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves s390 processor status word into the base kvm_run struct and keeps it up-to date on all userspace exits. The userspace ABI is broken by this, however there are no applications in the wild using this. A capability check is provided so users can verify the updated API exists. Cc: stable@kernel.org Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: x86: Add KVM_GET/SET_VCPU_EVENTSJan Kiszka2009-12-031-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | This new IOCTL exports all yet user-invisible states related to exceptions, interrupts, and NMIs. Together with appropriate user space changes, this fixes sporadic problems of vmsave/restore, live migration and system reset. [avi: future-proof abi by adding a flags field] Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: VMX: Report unexpected simultaneous exceptions as internal errorsAvi Kivity2009-12-031-0/+1
| | | | | | | | | | | | | | | | | | These happen when we trap an exception when another exception is being delivered; we only expect these with MCEs and page faults. If something unexpected happens, things probably went south and we're better off reporting an internal error and freezing. Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: Allow internal errors reported to userspace to carry extra dataAvi Kivity2009-12-031-0/+4
| | | | | | | | | | | | | | | | | | Usually userspace will freeze the guest so we can inspect it, but some internal state is not available. Add extra data to internal error reporting so we can expose it to the debugger. Extra data is specific to the suberror. Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: Reorder IOCTLs in main kvm.hJan Kiszka2009-12-031-118/+117
| | | | | | | | | | | | | | | | | | | | Obviously, people tend to extend this header at the bottom - more or less blindly. Ensure that deprecated stuff gets its own corner again by moving things to the top. Also add some comments and reindent IOCTLs to make them more readable and reduce the risk of number collisions. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: allow userspace to adjust kvmclock offsetGlauber Costa2009-12-031-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we migrate a kvm guest that uses pvclock between two hosts, we may suffer a large skew. This is because there can be significant differences between the monotonic clock of the hosts involved. When a new host with a much larger monotonic time starts running the guest, the view of time will be significantly impacted. Situation is much worse when we do the opposite, and migrate to a host with a smaller monotonic clock. This proposed ioctl will allow userspace to inform us what is the monotonic clock value in the source host, so we can keep the time skew short, and more importantly, never goes backwards. Userspace may also need to trigger the current data, since from the first migration onwards, it won't be reflected by a simple call to clock_gettime() anymore. [marcelo: future-proof abi with a flags field] [jan: fix KVM_GET_CLOCK by clearing flags field instead of checking it] Signed-off-by: Glauber Costa <glommer@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: Xen PV-on-HVM guest supportEd Swierk2009-12-031-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support for Xen PV-on-HVM guests can be implemented almost entirely in userspace, except for handling one annoying MSR that maps a Xen hypercall blob into guest address space. A generic mechanism to delegate MSR writes to userspace seems overkill and risks encouraging similar MSR abuse in the future. Thus this patch adds special support for the Xen HVM MSR. I implemented a new ioctl, KVM_XEN_HVM_CONFIG, that lets userspace tell KVM which MSR the guest will write to, as well as the starting address and size of the hypercall blobs (one each for 32-bit and 64-bit) that userspace has loaded from files. When the guest writes to the MSR, KVM copies one page of the blob from userspace to the guest. I've tested this patch with a hacked-up version of Gerd's userspace code, booting a number of guests (CentOS 5.3 i386 and x86_64, and FreeBSD 8.0-RC1 amd64) and exercising PV network and block devices. [jan: fix i386 build warning] [avi: future proof abi with a flags field] Signed-off-by: Ed Swierk <eswierk@aristanetworks.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | powerpc/kvm: Sync guest visible MMU stateAlexander Graf2009-12-081-0/+3
|/ | | | | | | | | | | | | Currently userspace has no chance to find out which virtual address space we're in and resolve addresses. While that is a big problem for migration, it's also unpleasent when debugging, as gdb and the monitor don't work on virtual addresses. This patch exports enough of the MMU segment state to userspace to make debugging work and thus also includes the groundwork for migration. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* KVM: VMX: Introduce KVM_SET_IDENTITY_MAP_ADDR ioctlSheng Yang2009-09-101-0/+2
| | | | | | | | | | Now KVM allow guest to modify guest's physical address of EPT's identity mapping page. (change from v1, discard unnecessary check, change ioctl to accept parameter address rather than value) Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: add ioeventfd supportGregory Haskins2009-09-101-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ioeventfd is a mechanism to register PIO/MMIO regions to trigger an eventfd signal when written to by a guest. Host userspace can register any arbitrary IO address with a corresponding eventfd and then pass the eventfd to a specific end-point of interest for handling. Normal IO requires a blocking round-trip since the operation may cause side-effects in the emulated model or may return data to the caller. Therefore, an IO in KVM traps from the guest to the host, causes a VMX/SVM "heavy-weight" exit back to userspace, and is ultimately serviced by qemu's device model synchronously before returning control back to the vcpu. However, there is a subclass of IO which acts purely as a trigger for other IO (such as to kick off an out-of-band DMA request, etc). For these patterns, the synchronous call is particularly expensive since we really only want to simply get our notification transmitted asychronously and return as quickly as possible. All the sychronous infrastructure to ensure proper data-dependencies are met in the normal IO case are just unecessary overhead for signalling. This adds additional computational load on the system, as well as latency to the signalling path. Therefore, we provide a mechanism for registration of an in-kernel trigger point that allows the VCPU to only require a very brief, lightweight exit just long enough to signal an eventfd. This also means that any clients compatible with the eventfd interface (which includes userspace and kernelspace equally well) can now register to be notified. The end result should be a more flexible and higher performance notification API for the backend KVM hypervisor and perhipheral components. To test this theory, we built a test-harness called "doorbell". This module has a function called "doorbell_ring()" which simply increments a counter for each time the doorbell is signaled. It supports signalling from either an eventfd, or an ioctl(). We then wired up two paths to the doorbell: One via QEMU via a registered io region and through the doorbell ioctl(). The other is direct via ioeventfd. You can download this test harness here: ftp://ftp.novell.com/dev/ghaskins/doorbell.tar.bz2 The measured results are as follows: qemu-mmio: 110000 iops, 9.09us rtt ioeventfd-mmio: 200100 iops, 5.00us rtt ioeventfd-pio: 367300 iops, 2.72us rtt I didn't measure qemu-pio, because I have to figure out how to register a PIO region with qemu's device model, and I got lazy. However, for now we can extrapolate based on the data from the NULLIO runs of +2.56us for MMIO, and -350ns for HC, we get: qemu-pio: 153139 iops, 6.53us rtt ioeventfd-hc: 412585 iops, 2.37us rtt these are just for fun, for now, until I can gather more data. Here is a graph for your convenience: http://developer.novell.com/wiki/images/7/76/Iofd-chart.png The conclusion to draw is that we save about 4us by skipping the userspace hop. -------------------- Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PIT support for HPET legacy modeBeth Kon2009-09-101-0/+6
| | | | | | | | | | | | | | | | | | | | | | | When kvm is in hpet_legacy_mode, the hpet is providing the timer interrupt and the pit should not be. So in legacy mode, the pit timer is destroyed, but the *state* of the pit is maintained. So if kvm or the guest tries to modify the state of the pit, this modification is accepted, *except* that the timer isn't actually started. When we exit hpet_legacy_mode, the current state of the pit (which is up to date since we've been accepting modifications) is used to restart the pit timer. The saved_mode code in kvm_pit_load_count temporarily changes mode to 0xff in order to destroy the timer, but then restores the actual value, again maintaining "current" state of the pit for possible later reenablement. [avi: add some reserved storage in the ioctl; make SET_PIT2 IOW] [marcelo: fix memory corruption due to reserved storage] Signed-off-by: Beth Kon <eak@us.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: remove old KVMTRACE support codeMarcelo Tosatti2009-09-101-30/+1
| | | | | | | Return EOPNOTSUPP for KVM_TRACE_ENABLE/PAUSE/DISABLE ioctls. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Return to userspace on emulation failureAvi Kivity2009-09-101-0/+7
| | | | | | | Instead of mindlessly retrying to execute the instruction, report the failure to userspace. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Break dependency between vcpu index in vcpus array and vcpu_id.Gleb Natapov2009-09-101-0/+2
| | | | | | | | | Archs are free to use vcpu_id as they see fit. For x86 it is used as vcpu's apic id. New ioctl is added to configure boot vcpu id that was assumed to be 0 till now. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Reorder ioctls in kvm.hAvi Kivity2009-09-101-5/+5
| | | | | | Somehow the VM ioctls got unsorted; resort. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Downsize max support MSI-X entry to 256Sheng Yang2009-09-101-1/+1
| | | | | | | | We only trap one page for MSI-X entry now, so it's 4k/(128/8) = 256 entries at most. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Allow PIT emulation without speaker portJan Kiszka2009-09-101-0/+12
| | | | | | | | | | | | | The in-kernel speaker emulation is only a dummy and also unneeded from the performance point of view. Rather, it takes user space support to generate sound output on the host, e.g. console beeps. To allow this, introduce KVM_CREATE_PIT2 which controls in-kernel speaker port emulation via a flag passed along the new IOCTL. It also leaves room for future extensions of the PIT configuration interface. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: irqfdGregory Haskins2009-09-101-0/+11
| | | | | | | | | | | | | | | | KVM provides a complete virtual system environment for guests, including support for injecting interrupts modeled after the real exception/interrupt facilities present on the native platform (such as the IDT on x86). Virtual interrupts can come from a variety of sources (emulated devices, pass-through devices, etc) but all must be injected to the guest via the KVM infrastructure. This patch adds a new mechanism to inject a specific interrupt to a guest using a decoupled eventfd mechnanism: Any legal signal on the irqfd (using eventfd semantics from either userspace or kernel) will translate into an injected interrupt in the guest at the next available interrupt window. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Add MCE supportHuang Ying2009-09-101-0/+20
| | | | | | | | | | | | The related MSRs are emulated. MCE capability is exported via extension KVM_CAP_MCE and ioctl KVM_X86_GET_MCE_CAP_SUPPORTED. A new vcpu ioctl command KVM_X86_SETUP_MCE is used to setup MCE emulation such as the mcg_cap. MCE is injected via vcpu ioctl command KVM_X86_SET_MCE. Extended machine-check state (MCG_EXT_P) and CMCI are not implemented. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Make kvm header C++ friendlynathan binkert2009-06-101-3/+3
| | | | | | | | | | Two things needed fixing: 1) g++ does not allow a named structure type within an anonymous union and 2) Avoid name clash between two padding fields within the same struct by giving them different names as is done elsewhere in the header. Signed-off-by: Nathan Binkert <nate@binkert.org> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Device assignment framework reworkSheng Yang2009-06-101-9/+17
| | | | | | | | | | | | | | | | | | | | | | | After discussion with Marcelo, we decided to rework device assignment framework together. The old problems are kernel logic is unnecessary complex. So Marcelo suggest to split it into a more elegant way: 1. Split host IRQ assign and guest IRQ assign. And userspace determine the combination. Also discard msi2intx parameter, userspace can specific KVM_DEV_IRQ_HOST_MSI | KVM_DEV_IRQ_GUEST_INTX in assigned_irq->flags to enable MSI to INTx convertion. 2. Split assign IRQ and deassign IRQ. Import two new ioctls: KVM_ASSIGN_DEV_IRQ and KVM_DEASSIGN_DEV_IRQ. This patch also fixed the reversed _IOR vs _IOW in definition(by deprecated the old interface). [avi: replace homemade bitcount() by hweight_long()] Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Enable MSI-X for KVM assigned deviceSheng Yang2009-06-101-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch finally enable MSI-X. What we need for MSI-X: 1. Intercept one page in MMIO region of device. So that we can get guest desired MSI-X table and set up the real one. Now this have been done by guest, and transfer to kernel using ioctl KVM_SET_MSIX_NR and KVM_SET_MSIX_ENTRY. 2. Information for incoming interrupt. Now one device can have more than one interrupt, and they are all handled by one workqueue structure. So we need to identify them. The previous patch enable gsi_msg_pending_bitmap get this done. 3. Mapping from host IRQ to guest gsi as well as guest gsi to real MSI/MSI-X message address/data. We used same entry number for the host and guest here, so that it's easy to find the correlated guest gsi. What we lack for now: 1. The PCI spec said nothing can existed with MSI-X table in the same page of MMIO region, except pending bits. The patch ignore pending bits as the first step (so they are always 0 - no pending). 2. The PCI spec allowed to change MSI-X table dynamically. That means, the OS can enable MSI-X, then mask one MSI-X entry, modify it, and unmask it. The patch didn't support this, and Linux also don't work in this way. 3. The patch didn't implement MSI-X mask all and mask single entry. I would implement the former in driver/pci/msi.c later. And for single entry, userspace should have reposibility to handle it. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Ioctls for init MSI-X entrySheng Yang2009-06-101-0/+18
| | | | | | | | | | | | | | Introduce KVM_SET_MSIX_NR and KVM_SET_MSIX_ENTRY two ioctls. This two ioctls are used by userspace to specific guest device MSI-X entry number and correlate MSI-X entry with GSI during the initialization stage. MSI-X should be well initialzed before enabling. Don't support change MSI-X entry number for now. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Fix overlapping check for memory slotsJan Kiszka2009-04-221-0/+2
| | | | | | | | | | | | When checking for overlapping slots on registration of a new one, kvm currently also considers zero-length (ie. deleted) slots and rejects requests incorrectly. This finally denies user space from joining slots. Fix the check by skipping deleted slots and advertise this via a KVM_CAP_JOIN_MEMORY_REGIONS_WORKS. Cc: stable@kernel.org Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 13:51:55 +0000