- 17 Oct, 2013 21 commits
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Paul Mackerras authored
This makes PR KVM allocate its kvm_vcpu structs from the kvm_vcpu_cache rather than having them embedded in the kvmppc_vcpu_book3s struct, which is allocated with vzalloc. The reason is to reduce the differences between PR and HV KVM in order to make is easier to have them coexist in one kernel binary. With this, the kvm_vcpu struct has a pointer to the kvmppc_vcpu_book3s struct. The pointer to the kvmppc_book3s_shadow_vcpu struct has moved from the kvmppc_vcpu_book3s struct to the kvm_vcpu struct, and is only present for 32-bit, since it is only used for 32-bit. Signed-off-by:
Paul Mackerras <paulus@samba.org> [agraf: squash in compile fix from Aneesh] Signed-off-by:
Alexander Graf <agraf@suse.de>
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Paul Mackerras authored
This adds a per-VM mutex to provide mutual exclusion between vcpus for accesses to and updates of the guest hashed page table (HPT). This also makes the code use single-byte writes to the HPT entry when updating of the reference (R) and change (C) bits. The reason for doing this, rather than writing back the whole HPTE, is that on non-PAPR virtual machines, the guest OS might be writing to the HPTE concurrently, and writing back the whole HPTE might conflict with that. Also, real hardware does single-byte writes to update R and C. The new mutex is taken in kvmppc_mmu_book3s_64_xlate() when reading the HPT and updating R and/or C, and in the PAPR HPT update hcalls (H_ENTER, H_REMOVE, etc.). Having the mutex means that we don't need to use a hypervisor lock bit in the HPT update hcalls, and we don't need to be careful about the order in which the bytes of the HPTE are updated by those hcalls. The other change here is to make emulated TLB invalidations (tlbie) effective across all vcpus. To do this we call kvmppc_mmu_pte_vflush for all vcpus in kvmppc_ppc_book3s_64_tlbie(). For 32-bit, this makes the setting of the accessed and dirty bits use single-byte writes, and makes tlbie invalidate shadow HPTEs for all vcpus. With this, PR KVM can successfully run SMP guests. Signed-off-by:
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Paul Mackerras authored
The implementation of H_ENTER in PR KVM has some errors: * With H_EXACT not set, if the HPTEG is full, we return H_PTEG_FULL as the return value of kvmppc_h_pr_enter, but the caller is expecting one of the EMULATE_* values. The H_PTEG_FULL needs to go in the guest's R3 instead. * With H_EXACT set, if the selected HPTE is already valid, the H_ENTER call should return a H_PTEG_FULL error. This fixes these errors and also makes it write only the selected HPTE, not the whole group, since only the selected HPTE has been modified. This also micro-optimizes the calculations involving pte_index and i. Signed-off-by:
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Paul Mackerras authored
64-bit POWER processors have a three-bit field for page protection in the hashed page table entry (HPTE). Currently we only interpret the two bits that were present in older versions of the architecture. The only defined combination that has the new bit set is 110, meaning read-only for supervisor and no access for user mode. This adds code to kvmppc_mmu_book3s_64_xlate() to interpret the extra bit appropriately. Signed-off-by:
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Paul Mackerras authored
Currently, PR KVM uses 4k pages for the host-side mappings of guest memory, regardless of the host page size. When the host page size is 64kB, we might as well use 64k host page mappings for guest mappings of 64kB and larger pages and for guest real-mode mappings. However, the magic page has to remain a 4k page. To implement this, we first add another flag bit to the guest VSID values we use, to indicate that this segment is one where host pages should be mapped using 64k pages. For segments with this bit set we set the bits in the shadow SLB entry to indicate a 64k base page size. When faulting in host HPTEs for this segment, we make them 64k HPTEs instead of 4k. We record the pagesize in struct hpte_cache for use when invalidating the HPTE. For now we restrict the segment containing the magic page (if any) to 4k pages. It should be possible to lift this restriction in future by ensuring that the magic 4k page is appropriately positioned within a host 64k page. Signed-off-by:
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Paul Mackerras authored
This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by:
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Paul Mackerras authored
Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by:
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Paul Mackerras authored
Commit 9d1ffdd8 ("KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX") added a call to kvmppc_load_up_altivec() that isn't guarded by CONFIG_ALTIVEC, causing a link failure when building a kernel without CONFIG_ALTIVEC set. This adds an #ifdef to fix this. Signed-off-by:
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Paul Mackerras authored
If we come out of a guest with an interrupt that we don't know about, instead of crashing the host with a BUG(), we now return to userspace with the exit reason set to KVM_EXIT_UNKNOWN and the trap vector in the hw.hardware_exit_reason field of the kvm_run structure, as is done on x86. Note that run->exit_reason is already set to KVM_EXIT_UNKNOWN at the beginning of kvmppc_handle_exit(). Signed-off-by:
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Paul Mackerras authored
This enables us to use the Processor Compatibility Register (PCR) on POWER7 to put the processor into architecture 2.05 compatibility mode when running a guest. In this mode the new instructions and registers that were introduced on POWER7 are disabled in user mode. This includes all the VSX facilities plus several other instructions such as ldbrx, stdbrx, popcntw, popcntd, etc. To select this mode, we have a new register accessible through the set/get_one_reg interface, called KVM_REG_PPC_ARCH_COMPAT. Setting this to zero gives the full set of capabilities of the processor. Setting it to one of the "logical" PVR values defined in PAPR puts the vcpu into the compatibility mode for the corresponding architecture level. The supported values are: 0x0f000002 Architecture 2.05 (POWER6) 0x0f000003 Architecture 2.06 (POWER7) 0x0f100003 Architecture 2.06+ (POWER7+) Since the PCR is per-core, the architecture compatibility level and the corresponding PCR value are stored in the struct kvmppc_vcore, and are therefore shared between all vcpus in a virtual core. Signed-off-by:
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Paul Mackerras authored
POWER7 and later IBM server processors have a register called the Program Priority Register (PPR), which controls the priority of each hardware CPU SMT thread, and affects how fast it runs compared to other SMT threads. This priority can be controlled by writing to the PPR or by use of a set of instructions of the form or rN,rN,rN which are otherwise no-ops but have been defined to set the priority to particular levels. This adds code to context switch the PPR when entering and exiting guests and to make the PPR value accessible through the SET/GET_ONE_REG interface. When entering the guest, we set the PPR as late as possible, because if we are setting a low thread priority it will make the code run slowly from that point on. Similarly, the first-level interrupt handlers save the PPR value in the PACA very early on, and set the thread priority to the medium level, so that the interrupt handling code runs at a reasonable speed. Acked-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Paul Mackerras authored
This adds the ability to have a separate LPCR (Logical Partitioning Control Register) value relating to a guest for each virtual core, rather than only having a single value for the whole VM. This corresponds to what real POWER hardware does, where there is a LPCR per CPU thread but most of the fields are required to have the same value on all active threads in a core. The per-virtual-core LPCR can be read and written using the GET/SET_ONE_REG interface. Userspace can can only modify the following fields of the LPCR value: DPFD Default prefetch depth ILE Interrupt little-endian TC Translation control (secondary HPT hash group search disable) We still maintain a per-VM default LPCR value in kvm->arch.lpcr, which contains bits relating to memory management, i.e. the Virtualized Partition Memory (VPM) bits and the bits relating to guest real mode. When this default value is updated, the update needs to be propagated to the per-vcore values, so we add a kvmppc_update_lpcr() helper to do that. Signed-off-by:
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Paul Mackerras authored
This makes the VRSAVE register value for a vcpu accessible through the GET/SET_ONE_REG interface on Book E systems (in addition to the existing GET/SET_SREGS interface), for consistency with Book 3S. Signed-off-by:
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Paul Mackerras authored
The yield count in the VPA is supposed to be incremented every time we enter the guest, and every time we exit the guest, so that its value is even when the vcpu is running in the guest and odd when it isn't. However, it's currently possible that we increment the yield count on the way into the guest but then find that other CPU threads are already exiting the guest, so we go back to nap mode via the secondary_too_late label. In this situation we don't increment the yield count again, breaking the relationship between the LSB of the count and whether the vcpu is in the guest. To fix this, we move the increment of the yield count to a point after we have checked whether other CPU threads are exiting. Signed-off-by:
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Paul Mackerras authored
This moves the code in book3s_hv_rmhandlers.S that reads any pending interrupt from the XICS interrupt controller, and works out whether it is an IPI for the guest, an IPI for the host, or a device interrupt, into a new function called kvmppc_read_intr. Later patches will need this. Signed-off-by:
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Paul Mackerras authored
We have two paths into and out of the low-level guest entry and exit code: from a vcpu task via kvmppc_hv_entry_trampoline, and from the system reset vector for an offline secondary thread on POWER7 via kvm_start_guest. Currently both just branch to kvmppc_hv_entry to enter the guest, and on guest exit, we test the vcpu physical thread ID to detect which way we came in and thus whether we should return to the vcpu task or go back to nap mode. In order to make the code flow clearer, and to keep the code relating to each flow together, this turns kvmppc_hv_entry into a subroutine that follows the normal conventions for call and return. This means that kvmppc_hv_entry_trampoline() and kvmppc_hv_entry() now establish normal stack frames, and we use the normal stack slots for saving return addresses rather than local_paca->kvm_hstate.vmhandler. Apart from that this is mostly moving code around unchanged. Signed-off-by:
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Paul Mackerras authored
The H_CONFER hypercall is used when a guest vcpu is spinning on a lock held by another vcpu which has been preempted, and the spinning vcpu wishes to give its timeslice to the lock holder. We implement this in the straightforward way using kvm_vcpu_yield_to(). Signed-off-by:
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Paul Mackerras authored
The VRSAVE register value for a vcpu is accessible through the GET/SET_SREGS interface for Book E processors, but not for Book 3S processors. In order to make this accessible for Book 3S processors, this adds a new register identifier for GET/SET_ONE_REG, and adds the code to implement it. Signed-off-by:
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Paul Mackerras authored
This allows guests to have a different timebase origin from the host. This is needed for migration, where a guest can migrate from one host to another and the two hosts might have a different timebase origin. However, the timebase seen by the guest must not go backwards, and should go forwards only by a small amount corresponding to the time taken for the migration. Therefore this provides a new per-vcpu value accessed via the one_reg interface using the new KVM_REG_PPC_TB_OFFSET identifier. This value defaults to 0 and is not modified by KVM. On entering the guest, this value is added onto the timebase, and on exiting the guest, it is subtracted from the timebase. This is only supported for recent POWER hardware which has the TBU40 (timebase upper 40 bits) register. Writing to the TBU40 register only alters the upper 40 bits of the timebase, leaving the lower 24 bits unchanged. This provides a way to modify the timebase for guest migration without disturbing the synchronization of the timebase registers across CPU cores. The kernel rounds up the value given to a multiple of 2^24. Timebase values stored in KVM structures (struct kvm_vcpu, struct kvmppc_vcore, etc.) are stored as host timebase values. The timebase values in the dispatch trace log need to be guest timebase values, however, since that is read directly by the guest. This moves the setting of vcpu->arch.dec_expires on guest exit to a point after we have restored the host timebase so that vcpu->arch.dec_expires is a host timebase value. Signed-off-by:
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Paul Mackerras authored
Currently we are not saving and restoring the SIAR and SDAR registers in the PMU (performance monitor unit) on guest entry and exit. The result is that performance monitoring tools in the guest could get false information about where a program was executing and what data it was accessing at the time of a performance monitor interrupt. This fixes it by saving and restoring these registers along with the other PMU registers on guest entry/exit. This also provides a way for userspace to access these values for a vcpu via the one_reg interface. Signed-off-by:
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Michael Neuling authored
This reserves space in get/set_one_reg ioctl for the extra guest state needed for POWER8. It doesn't implement these at all, it just reserves them so that the ABI is defined now. A few things to note here: - This add *a lot* state for transactional memory. TM suspend mode, this is unavoidable, you can't simply roll back all transactions and store only the checkpointed state. I've added this all to get/set_one_reg (including GPRs) rather than creating a new ioctl which returns a struct kvm_regs like KVM_GET_REGS does. This means we if we need to extract the TM state, we are going to need a bucket load of IOCTLs. Hopefully most of the time this will not be needed as we can look at the MSR to see if TM is active and only grab them when needed. If this becomes a bottle neck in future we can add another ioctl to grab all this state in one go. - The TM state is offset by 0x80000000. - For TM, I've done away with VMX and FP and created a single 64x128 bit VSX register space. - I've left a space of 1 (at 0x9c) since Paulus needs to add a value which applies to POWER7 as well. Signed-off-by:
Michael Neuling <mikey@neuling.org> Signed-off-by:
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- 16 Oct, 2013 2 commits
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git://git.linaro.org/people/cdall/linux-kvm-armGleb Natapov authored
Updates for KVM/ARM including cpu=host and Cortex-A7 support
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Christoffer Dall authored
Some strange character leaped into the documentation, which makes git-send-email behave quite strangely. Get rid of this before it bites anyone else. Cc: Anup Patel <anup.patel@linaro.org> Signed-off-by:Christoffer Dall <christoffer.dall@linaro.org>
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- 15 Oct, 2013 1 commit
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chai wen authored
Page pinning is not mandatory in kvm async page fault processing since after async page fault event is delivered to a guest it accesses page once again and does its own GUP. Drop the FOLL_GET flag in GUP in async_pf code, and do some simplifying in check/clear processing. Suggested-by:
Gleb Natapov <gleb@redhat.com> Signed-off-by:
Gu zheng <guz.fnst@cn.fujitsu.com> Signed-off-by:
chai wen <chaiw.fnst@cn.fujitsu.com> Signed-off-by:
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- 14 Oct, 2013 7 commits
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Christoffer Dall authored
Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by:
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Christoffer Dall authored
Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by:
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Christoffer Dall authored
Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by:
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Christoffer Dall authored
Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by:
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Christoffer Dall authored
Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by:
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Christoffer Dall authored
The KVM_HPAGE_DEFINES are a little artificial on ARM, since the huge page size is statically defined at compile time and there is only a single huge page size. Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by:
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Christoffer Dall authored
The gfn_to_index function relies on huge page defines which either may not make sense on systems that don't support huge pages or are defined in an unconvenient way for other architectures. Since this is x86-specific, move the function to arch/x86/include/asm/kvm_host.h. Signed-off-by:
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- 13 Oct, 2013 3 commits
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Jonathan Austin authored
This patch adds support for running Cortex-A7 guests on Cortex-A7 hosts. As Cortex-A7 is architecturally compatible with A15, this patch is largely just generalising existing code. Areas where 'implementation defined' behaviour is identical for A7 and A15 is moved to allow it to be used by both cores. The check to ensure that coprocessor register tables are sorted correctly is also moved in to 'common' code to avoid each new cpu doing its own check (and possibly forgetting to do so!) Signed-off-by:
Jonathan Austin <jonathan.austin@arm.com> Acked-by:
Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:
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Jonathan Austin authored
The T{0,1}SZ fields of TTBCR are 3 bits wide when using the long descriptor format. Likewise, the T0SZ field of the HTCR is 3-bits. KVM currently defines TTBCR_T{0,1}SZ as 3, not 7. The T0SZ mask is used to calculate the value for the HTCR, both to pick out TTBCR.T0SZ and mask off the equivalent field in the HTCR during read-modify-write. The incorrect mask size causes the (UNKNOWN) reset value of HTCR.T0SZ to leak in to the calculated HTCR value. Linux will hang when initializing KVM if HTCR's reset value has bit 2 set (sometimes the case on A7/TC2) Fixing T0SZ allows A7 cores to boot and T1SZ is also fixed for completeness. Signed-off-by: -
Jonathan Austin authored
KVM does not have a notion of multiple clusters for CPUs, just a linear array of CPUs. When using a system with cores in more than one cluster, the current method for calculating the virtual MPIDR will leak the (physical) cluster information into the virtual MPIDR. One effect of this is that Linux under KVM fails to boot multiple CPUs that aren't in the 0th cluster. This patch does away with exposing the real MPIDR fields in favour of simply using the virtual CPU number (but preserving the U bit, as before). Signed-off-by:
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- 10 Oct, 2013 1 commit
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Arthur Chunqi Li authored
This patch contains the following two changes: 1. Fix the bug in nested preemption timer support. If vmexit L2->L0 with some reasons not emulated by L1, preemption timer value should be save in such exits. 2. Add support of "Save VMX-preemption timer value" VM-Exit controls to nVMX. With this patch, nested VMX preemption timer features are fully supported. Signed-off-by:
Arthur Chunqi Li <yzt356@gmail.com> Reviewed-by:
Paolo Bonzini <pbonzini@redhat.com>
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- 03 Oct, 2013 5 commits
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Paolo Bonzini authored
kvm_mmu initialization is mostly filling in function pointers, there is no way for it to fail. Clean up unused return values. Signed-off-by:
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Paolo Bonzini authored
They do the same thing, and destroy_kvm_mmu can be confused with kvm_mmu_destroy. Signed-off-by:
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Paolo Bonzini authored
The new_cr3 MMU callback has been a wrapper for mmu_free_roots since commit e676505a (KVM: MMU: Force cr3 reload with two dimensional paging on mov cr3 emulation, 2012-07-08). The commit message mentioned that "mmu_free_roots() is somewhat of an overkill, but fixing that is more complicated and will be done after this minimal fix". One year has passed, and no one really felt the need to do a different fix. Wrap the call with a kvm_mmu_new_cr3 function for clarity, but remove the callback. Signed-off-by:
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Paolo Bonzini authored
The free MMU callback has been a wrapper for mmu_free_roots since mmu_free_roots itself was introduced (commit 17ac10ad, [PATCH] KVM: MU: Special treatment for shadow pae root pages, 2007-01-05), and has always been the same for all MMU cases. Remove the indirection as it is useless. Signed-off-by:
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Paolo Bonzini authored
This makes the interface more deterministic for userspace, which can expect (after configuring only the features it supports) to get exactly the same state from the kernel, independent of the host CPU and kernel version. Suggested-by:
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