- 14 Jan, 2013 8 commits
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Takuya Yoshikawa authored
If the userspace starts dirty logging for a large slot, say 64GB of memory, kvm_mmu_slot_remove_write_access() needs to hold mmu_lock for a long time such as tens of milliseconds. This patch controls the lock hold time by asking the scheduler if we need to reschedule for others. One penalty for this is that we need to flush TLBs before releasing mmu_lock. But since holding mmu_lock for a long time does affect not only the guest, vCPU threads in other words, but also the host as a whole, we should pay for that. In practice, the cost will not be so high because we can protect a fair amount of memory before being rescheduled: on my test environment, cond_resched_lock() was called only once for protecting 12GB of memory even without THP. We can also revisit Avi's "unlocked TLB flush" work later for completely suppressing extra TLB flushes if needed. Reviewed-by:
Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by:
Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by:
Gleb Natapov <gleb@redhat.com>
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Takuya Yoshikawa authored
Better to place mmu_lock handling and TLB flushing code together since this is a self-contained function. Reviewed-by:
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Takuya Yoshikawa authored
No reason to make callers take mmu_lock since we do not need to protect kvm_mmu_change_mmu_pages() and kvm_mmu_slot_remove_write_access() together by mmu_lock in kvm_arch_commit_memory_region(): the former calls kvm_mmu_commit_zap_page() and flushes TLBs by itself. Note: we do not need to protect kvm->arch.n_requested_mmu_pages by mmu_lock as can be seen from the fact that it is read locklessly. Reviewed-by:
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Takuya Yoshikawa authored
Not needed any more. Reviewed-by:
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Takuya Yoshikawa authored
This makes it possible to release mmu_lock and reschedule conditionally in a later patch. Although this may increase the time needed to protect the whole slot when we start dirty logging, the kernel should not allow the userspace to trigger something that will hold a spinlock for such a long time as tens of milliseconds: actually there is no limit since it is roughly proportional to the number of guest pages. Another point to note is that this patch removes the only user of slot_bitmap which will cause some problems when we increase the number of slots further. Reviewed-by:
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Takuya Yoshikawa authored
No longer need to care about the mapping level in this function. Reviewed-by:
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Takuya Yoshikawa authored
Calling kvm_mmu_slot_remove_write_access() for a deleted slot does nothing but search for non-existent mmu pages which have mappings to that deleted memory; this is safe but a waste of time. Since we want to make the function rmap based in a later patch, in a manner which makes it unsafe to be called for a deleted slot, we makes the caller see if the slot is non-zero and being dirty logged. Reviewed-by:
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- 10 Jan, 2013 11 commits
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Cornelia Huck authored
trace_kvm_userspace_exit has been missing the KVM_EXIT_WATCHDOG exit. CC: Bharat Bhushan <r65777@freescale.com> Signed-off-by:
Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by:
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Xiao Guangrong authored
We have two issues in current code: - if target gfn is used as its page table, guest will refault then kvm will use small page size to map it. We need two #PF to fix its shadow page table - sometimes, say a exception is triggered during vm-exit caused by #PF (see handle_exception() in vmx.c), we remove all the shadow pages shadowed by the target gfn before go into page fault path, it will cause infinite loop: delete shadow pages shadowed by the gfn -> try to use large page size to map the gfn -> retry the access ->... To fix these, we can adjust page size early if the target gfn is used as page table Signed-off-by:
Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by:
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Xiao Guangrong authored
If the write-fault access is from supervisor and CR0.WP is not set on the vcpu, kvm will fix it by adjusting pte access - it sets the W bit on pte and clears U bit. This is the chance that kvm can change pte access from readonly to writable Unfortunately, the pte access is the access of 'direct' shadow page table, means direct sp.role.access = pte_access, then we will create a writable spte entry on the readonly shadow page table. It will cause Dirty bit is not tracked when two guest ptes point to the same large page. Note, it does not have other impact except Dirty bit since cr0.wp is encoded into sp.role It can be fixed by adjusting pte access before establishing shadow page table. Also, after that, no mmu specified code exists in the common function and drop two parameters in set_spte Signed-off-by:
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Alexander Graf authored
We need to be able to read and write the contents of the EPR register from user space. This patch implements that logic through the ONE_REG API and declares its (never implemented) SREGS counterpart as deprecated. Signed-off-by:Alexander Graf <agraf@suse.de>
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Alexander Graf authored
The External Proxy Facility in FSL BookE chips allows the interrupt controller to automatically acknowledge an interrupt as soon as a core gets its pending external interrupt delivered. Today, user space implements the interrupt controller, so we need to check on it during such a cycle. This patch implements logic for user space to enable EPR exiting, disable EPR exiting and EPR exiting itself, so that user space can acknowledge an interrupt when an external interrupt has successfully been delivered into the guest vcpu. Signed-off-by: -
Alexander Graf authored
The EPR register is potentially valid for PR KVM as well, so we need to emulate accesses to it. It's only defined for reading, so only handle the mfspr case. Signed-off-by: -
Alexander Graf authored
When injecting an interrupt into guest context, we usually don't need to check for requests anymore. At least not until today. With the introduction of EPR, we will have to create a request when the guest has successfully accepted an external interrupt though. So we need to prepare the interrupt delivery to abort guest entry gracefully. Otherwise we'd delay the EPR request. Signed-off-by: -
Mihai Caraman authored
On mfspr/mtspr emulation path Book3E's MMUCFG SPR with value 1015 clashes with G4's MSSSR0 SPR. Move MSSSR0 emulation from generic part to Books3S. MSSSR0 also clashes with Book3S's DABRX SPR. DABRX was not explicitly handled so Book3S execution flow will behave as before. Signed-off-by:
Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by:
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Alexander Graf authored
When running on top of pHyp, the hypercall instruction "sc 1" goes straight into pHyp without trapping in supervisor mode. So if we want to support PAPR guest in this configuration we need to add a second way of accessing PAPR hypercalls, preferably with the exact same semantics except for the instruction. So let's overlay an officially reserved instruction and emulate PAPR hypercalls whenever we hit that one. Signed-off-by: -
Alexander Graf authored
When we hit an emulation result that we didn't expect, that is an error, but it's nothing that warrants a BUG(), because it can be guest triggered. So instead, let's only WARN() the user that this happened. Signed-off-by: -
Mihai Caraman authored
Reflect the uapi folder change in SREGS API documentation. Signed-off-by:
Amos Kong <kongjianjun@gmail.com> Signed-off-by:
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- 09 Jan, 2013 9 commits
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Christian Borntraeger authored
In rare cases a virtio command might try to issue a ccw before a former ccw was answered with a tsch. This will cause CC=2 (busy). Lets just retry in that case. Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
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Cornelia Huck authored
Dynamically allocate any data structures like ccw used when doing channel I/O. Otherwise, we'd need to add extra serialization for the different callbacks using the same data structures. Reported-by:
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Avi Kivity authored
Opcodes: TEST CMP ADD ADC SUB SBB XOR OR AND Acked-by:
Avi Kivity <avi.kivity@gmail.com> Signed-off-by:
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Avi Kivity authored
Acked-by:
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Avi Kivity authored
Acked-by:
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Avi Kivity authored
Acked-by:
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Avi Kivity authored
Instead of disabling writeback via OP_NONE, just specify NoWrite. Acked-by:
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Avi Kivity authored
Acked-by:
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Avi Kivity authored
We emulate arithmetic opcodes by executing a "similar" (same operation, different operands) on the cpu. This ensures accurate emulation, esp. wrt. eflags. However, the prologue and epilogue around the opcode is fairly long, consisting of a switch (for the operand size) and code to load and save the operands. This is repeated for every opcode. This patch introduces an alternative way to emulate arithmetic opcodes. Instead of the above, we have four (three on i386) functions consisting of just the opcode and a ret; one for each operand size. For example: .align 8 em_notb: not %al ret .align 8 em_notw: not %ax ret .align 8 em_notl: not %eax ret .align 8 em_notq: not %rax ret The prologue and epilogue are shared across all opcodes. Note the functions use a special calling convention; notably eflags is an input/output parameter and is not clobbered. Rather than dispatching the four functions through a jump table, the functions are declared as a constant size (8) so their address can be calculated. Acked-by:
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- 08 Jan, 2013 2 commits
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Marcelo Tosatti authored
CPL is always 0 when in real mode, and always 3 when virtual 8086 mode. Using values other than those can cause failures on operations that check CPL. Reviewed-by:
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Gleb Natapov authored
Fix compilation warning. Signed-off-by:
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- 07 Jan, 2013 9 commits
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Gleb Natapov authored
MMU code tries to avoid if()s HW is not able to predict reliably by using bitwise operation to streamline code execution, but in case of a dirty bit folding this gives us nothing since write_fault is checked right before the folding code. Lets just piggyback onto the if() to make code more clear. Signed-off-by:
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Gleb Natapov authored
trace_kvm_mmu_delay_free_pages() is no longer used. Signed-off-by:
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Cornelia Huck authored
Add a new capability, KVM_CAP_S390_CSS_SUPPORT, which will pass intercepts for channel I/O instructions to userspace. Only I/O instructions interacting with I/O interrupts need to be handled in-kernel: - TEST PENDING INTERRUPTION (tpi) dequeues and stores pending interrupts entirely in-kernel. - TEST SUBCHANNEL (tsch) dequeues pending interrupts in-kernel and exits via KVM_EXIT_S390_TSCH to userspace for subchannel- related processing. Reviewed-by:
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Cornelia Huck authored
Make s390 support KVM_ENABLE_CAP. Reviewed-by:
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Cornelia Huck authored
Explicitely catch all channel I/O related instructions intercepts in the kernel and set condition code 3 for them. This paves the way for properly handling these instructions later on. Note: This is not architecture compliant (the previous code wasn't either) since setting cc 3 is not the correct thing to do for some of these instructions. For Linux guests, however, it still has the intended effect of stopping css probing. Reviewed-by:
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Cornelia Huck authored
Add support for injecting machine checks (only repressible conditions for now). This is a bit more involved than I/O interrupts, for these reasons: - Machine checks come in both floating and cpu varieties. - We don't have a bit for machine checks enabling, but have to use a roundabout approach with trapping PSW changing instructions and watching for opened machine checks. Reviewed-by:
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Cornelia Huck authored
Add support for handling I/O interrupts (standard, subchannel-related ones and rudimentary adapter interrupts). The subchannel-identifying parameters are encoded into the interrupt type. I/O interrupts are floating, so they can't be injected on a specific vcpu. Reviewed-by:
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Cornelia Huck authored
Introduce helper functions for decoding the various base/displacement instruction formats. Reviewed-by:
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Cornelia Huck authored
These tables are never modified. Reviewed-by:
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- 02 Jan, 2013 1 commit
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Gleb Natapov authored
With emulate_invalid_guest_state=0 if a vcpu is in real mode VMX can enter the vcpu with smaller segment limit than guest configured. If the guest tries to access pass this limit it will get #GP at which point instruction will be emulated with correct segment limit applied. If during the emulation IO is detected it is not handled correctly. Vcpu thread should exit to userspace to serve the IO, but it returns to the guest instead. Since emulation is not completed till userspace completes the IO the faulty instruction is re-executed ad infinitum. The patch fixes that by exiting to userspace if IO happens during instruction emulation. Reported-by:
Alex Williamson <alex.williamson@redhat.com> Signed-off-by:
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