- 05 3月, 2012 5 次提交
-
-
由 Paul Mackerras 提交于
This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Paul Mackerras 提交于
This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Scott Wood 提交于
Decrementers are now properly driven by TCR/TSR, and the guest has full read/write access to these registers. The decrementer keeps ticking (and setting the TSR bit) regardless of whether the interrupts are enabled with TCR. The decrementer stops at zero, rather than going negative. Decrementers (and FITs, once implemented) are delivered as level-triggered interrupts -- dequeued when the TSR bit is cleared, not on delivery. Signed-off-by: NLiu Yu <yu.liu@freescale.com> [scottwood@freescale.com: significant changes] Signed-off-by: NScott Wood <scottwood@freescale.com> Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Scott Wood 提交于
This function also updates paravirt int_pending, so rename it to be more obvious that this is a collection of checks run prior to (re)entering a guest. Signed-off-by: NScott Wood <scottwood@freescale.com> Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Scott Wood 提交于
This implements a shared-memory API for giving host userspace access to the guest's TLB. Signed-off-by: NScott Wood <scottwood@freescale.com> Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
- 26 9月, 2011 1 次提交
-
-
由 Alexander Graf 提交于
There are multiple features in PowerPC KVM that can now be enabled depending on the user's wishes. Some of the combinations don't make sense or don't work though. So this patch adds a way to check if the executing environment would actually be able to run the guest properly. It also adds sanity checks if PVR is set (should always be true given the current code flow), if PAPR is only used with book3s_64 where it works and that HV KVM is only used in PAPR mode. Signed-off-by: NAlexander Graf <agraf@suse.de>
-
- 12 7月, 2011 8 次提交
-
-
由 Paul Mackerras 提交于
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: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 Paul Mackerras 提交于
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: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 David Gibson 提交于
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: NDavid Gibson <david@gibson.dropbear.id.au> Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 Paul Mackerras 提交于
This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 Paul Mackerras 提交于
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: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 Paul Mackerras 提交于
Instead of doing the kvm_guest_enter/exit() and local_irq_dis/enable() calls in powerpc.c, this moves them down into the subarch-specific book3s_pr.c and booke.c. This eliminates an extra local_irq_enable() call in book3s_pr.c, and will be needed for when we do SMT4 guest support in the book3s hypervisor mode code. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 Paul Mackerras 提交于
This arranges for the top-level arch/powerpc/kvm/powerpc.c file to pass down some of the calls it gets to the lower-level subarchitecture specific code. The lower-level implementations (in booke.c and book3s.c) are no-ops. The coming book3s_hv.c will need this. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
由 Scott Wood 提交于
This is a shared page used for paravirtualization. It is always present in the guest kernel's effective address space at the address indicated by the hypercall that enables it. The physical address specified by the hypercall is not used, as e500 does not have real mode. Signed-off-by: NScott Wood <scottwood@freescale.com> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
- 22 5月, 2011 1 次提交
-
-
由 Scott Wood 提交于
Signed-off-by: NScott Wood <scottwood@freescale.com> Signed-off-by: NAlexander Graf <agraf@suse.de>
-
- 24 10月, 2010 1 次提交
-
-
由 Alexander Graf 提交于
To communicate with KVM directly we need to plumb some sort of interface between the guest and KVM. Usually those interfaces use hypercalls. This hypercall implementation is described in the last patch of the series in a special documentation file. Please read that for further information. This patch implements stubs to handle KVM PPC hypercalls on the host and guest side alike. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
- 17 5月, 2010 3 次提交
-
-
由 Alexander Graf 提交于
The host shadow mmu code needs to get initialized. It needs to fetch a segment it can use to put shadow PTEs into. That initialization code was in generic code, which is icky. Let's move it over to the respective MMU file. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
We already have some inline fuctions we use to access vcpu or svcpu structs, depending on whether we're on booke or book3s. Since we just put a few more registers into the svcpu, we also need to make sure the respective callbacks are available and get used. So this patch moves direct use of the now in the svcpu struct fields to inline function calls. While at it, it also moves the definition of those inline function calls to respective header files for booke and book3s, greatly improving readability. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
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: NAlexander Graf <agraf@suse.de> v2 -> v3: - Add CAP for unset irq Signed-off-by: NAvi Kivity <avi@redhat.com>
-
- 25 4月, 2010 4 次提交
-
-
由 Alexander Graf 提交于
The PowerPC specification always lists bits from MSB to LSB. That is really confusing when you're trying to write C code, because it fits in pretty badly with the normal (1 << xx) schemes. So I came up with some nice wrappers that allow to get and set fields in a u64 with bit numbers exactly as given in the spec. That makes the code in KVM and the spec easier comparable. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
Emulation of an instruction can have different outcomes. It can succeed, fail, require MMIO, do funky BookE stuff - or it can just realize something's odd and will be fixed the next time around. Exactly that is what EMULATE_AGAIN means. Using that flag we can now tell the caller that nothing happened, but we still want to go back to the guest and see what happens next time we come around. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
The guest I was trying to get to run uses the LHA and LHAU instructions. Those instructions basically do a load, but also sign extend the result. Since we need to fill our registers by hand when doing MMIO, we also need to sign extend manually. This patch implements sign extended MMIO and the LHA(U) instructions. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
Right now MMIO access can only happen for GPRs and is at most 32 bit wide. That's actually enough for almost all types of hardware out there. Unfortunately, the guest I was using used FPU writes to MMIO regions, so it ended up writing 64 bit MMIOs using FPRs and QPRs. So let's add code to handle those odd cases too. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
- 01 3月, 2010 6 次提交
-
-
由 Alexander Graf 提交于
Commit 7d01b4c3ed2bb33ceaf2d270cb4831a67a76b51b introduced PACA backed vcpu values. With this patch, when a userspace app was setting GPRs before it was actually first loaded, the set values get discarded. This is because vcpu_load loads them from the vcpu backing store that we use whenever we're not owning the PACA. That behavior is not really a major problem, because we don't need it for qemu. Other users (like kvmctl) do have problems with it though, so let's better do it right. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
Book3S needs some flags in SRR1 to get to know details about an interrupt. One such example is the trap instruction. It tells the guest kernel that a program interrupt is due to a trap using a bit in SRR1. This patch implements above behavior, making WARN_ON behave like WARN_ON. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
We now have helpers for the GPRs, so let's also add some for CR and XER. Having them in the PACA simplifies code a lot, as we don't need to care about where to store CC or not to overflow any integers. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
All code in PPC KVM currently accesses gprs in the vcpu struct directly. While there's nothing wrong with that wrt the current way gprs are stored and loaded, it doesn't suffice for the PACA acceleration that will follow in this patchset. So let's just create little wrapper inline functions that we call whenever a GPR needs to be read from or written to. The compiled code shouldn't really change at all for now. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Alexander Graf 提交于
We treated the DEC interrupt like an edge based one. This is not true for Book3s. The DEC keeps firing until mtdec is issued again and thus clears the interrupt line. So let's implement this logic in KVM too. This patch moves the line clearing from the firing of the interrupt to the mtdec emulation. This makes PPC64 guests work without AGGRESSIVE_DEC defined. Signed-off-by: NAlexander Graf <agraf@suse.de> Acked-by: NAcked-by: Hollis Blanchard <hollis@penguinppc.org> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
- 05 11月, 2009 1 次提交
-
-
由 Alexander Graf 提交于
This is the of entry / exit code. In order to switch between host and guest context, we need to switch register state and call the exit code handler on exit. This assembly file does exactly that. To finally enter the guest it calls into book3s_64_slb.S. On exit it gets jumped at from book3s_64_slb.S too. Signed-off-by: NAlexander Graf <agraf@suse.de> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
- 24 3月, 2009 6 次提交
-
-
由 Hollis Blanchard 提交于
After the rewrite of KVM's debug support, this code doesn't even build any more. Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
When itlb or dtlb miss happens, E500 needs to update some mmu registers. So that the auto-load mechanism can work on E500 when write a tlb entry. Signed-off-by: NLiu Yu <yu.liu@freescale.com> Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
e500 will provide its own implementation of these. Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
Passing just the TLB index will ease an e500 implementation. Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
- 31 12月, 2008 4 次提交
-
-
由 Hollis Blanchard 提交于
Formerly, we used to maintain a per-vcpu shadow TLB and on every entry to the guest would load this array into the hardware TLB. This consumed 1280 bytes of memory (64 entries of 16 bytes plus a struct page pointer each), and also required some assembly to loop over the array on every entry. Instead of saving a copy in memory, we can just store shadow mappings directly into the hardware TLB, accepting that the host kernel will clobber these as part of the normal 440 TLB round robin. When we do that we need less than half the memory, and we have decreased the exit handling time for all guest exits, at the cost of increased number of TLB misses because the host overwrites some guest entries. These savings will be increased on processors with larger TLBs or which implement intelligent flush instructions like tlbivax (which will avoid the need to walk arrays in software). In addition to that and to the code simplification, we have a greater chance of leaving other host userspace mappings in the TLB, instead of forcing all subsequent tasks to re-fault all their mappings. Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
KVM on 440 has always been able to handle large guest mappings with 4K host pages -- we must, since the guest kernel uses 256MB mappings. This patch makes KVM work when the host has large pages too (tested with 64K). Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
In kvmppc_deliver_interrupt is just one case left in the switch and it is a rare one (less than 8%) when looking at the exit numbers. Therefore we can at least drop the switch/case and if an if. I inserted an unlikely too, but that's open for discussion. In kvmppc_can_deliver_interrupt all frequent cases are in the default case. I know compilers are smart but we can make it easier for them. By writing down all options and removing the default case combined with the fact that ithe values are constants 0..15 should allow the compiler to write an easy jump table. Modifying kvmppc_can_deliver_interrupt pointed me to the fact that gcc seems to be unable to reduce priority_exception[x] to a build time constant. Therefore I changed the usage of the translation arrays in the interrupt delivery path completely. It is now using priority without translation to irq on the full irq delivery path. To be able to do that ivpr regs are stored by their priority now. Additionally the decision made in kvmppc_can_deliver_interrupt is already sufficient to get the value of interrupt_msr_mask[x]. Therefore we can replace the 16x4byte array used here with a single 4byte variable (might still be one miss, but the chance to find this in cache should be better than the right entry of the whole array). Signed-off-by: NChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-
由 Hollis Blanchard 提交于
This patch doesn't yet move all 44x-specific data into the new structure, but is the first step down that path. In the future we may also want to create a struct kvm_vcpu_booke. Based on patch from Liu Yu <yu.liu@freescale.com>. Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
-