- 16 Oct, 2018 36 commits
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Sean Christopherson authored
Do not unconditionally call clear_atomic_switch_msr() when updating EFER. This adds up to four unnecessary VMWrites in the case where guest_efer != host_efer, e.g. if the load_on_{entry,exit} bits were already set. Signed-off-by:Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Reset the vm_{entry,exit}_controls_shadow variables as well as the segment cache after loading a new VMCS in vmx_switch_vmcs(). The shadows/cache track VMCS data, i.e. they're stale every time we switch to a new VMCS regardless of reason. This fixes a bug where stale control shadows would be consumed after a nested VMExit due to a failed consistency check. Suggested-by: -
Sean Christopherson authored
Write VM_EXIT_CONTROLS using vm_exit_controls_init() when configuring vmcs02, otherwise vm_exit_controls_shadow will be stale. EFER in particular can be corrupted if VM_EXIT_LOAD_IA32_EFER is not updated due to an incorrect shadow optimization, which can crash L0 due to EFER not being loaded on exit. This does not occur with the current code base simply because update_transition_efer() unconditionally clears VM_EXIT_LOAD_IA32_EFER before conditionally setting it, and because a nested guest always starts with VM_EXIT_LOAD_IA32_EFER clear, i.e. we'll only ever unnecessarily clear the bit. That is, until someone optimizes update_transition_efer()... Signed-off-by:
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Sean Christopherson authored
An invalid EPTP causes a VMFail(VMXERR_ENTRY_INVALID_CONTROL_FIELD), not a VMExit. Signed-off-by:
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Sean Christopherson authored
Invalid host state related to loading EFER on VMExit causes a VMFail(VMXERR_ENTRY_INVALID_HOST_STATE_FIELD), not a VMExit. Signed-off-by:
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Wei Yang authored
update_memslots() is only called by __kvm_set_memory_region(), in which "change" is calculated and indicates how to adjust slots->used_slots * increase by one if it is KVM_MR_CREATE * decrease by one if it is KVM_MR_DELETE * not change for others This patch adjusts slots->used_slots in update_memslots() based on "change" value instead of re-calculate those states again. Signed-off-by:
Wei Yang <richard.weiyang@gmail.com> Signed-off-by:
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Jim Mattson authored
When bit 3 (corresponding to CR0.TS) of the VMCS12 cr0_guest_host_mask field is clear, the VMCS12 guest_cr0 field does not necessarily hold the current value of the L2 CR0.TS bit, so the code that checked for L2's CR0.TS bit being set was incorrect. Moreover, I'm not sure that the CR0.TS check was adequate. (What if L2's CR0.EM was set, for instance?) Fortunately, lazy FPU has gone away, so L0 has lost all interest in intercepting #NM exceptions. See commit bd7e5b08 ("KVM: x86: remove code for lazy FPU handling"). Therefore, there is no longer any question of which hypervisor gets first dibs. The #NM VM-exit should always be reflected to L1. (Note that the corresponding bit must be set in the VMCS12 exception_bitmap field for there to be an #NM VM-exit at all.) Fixes: ccf9844e ("kvm, vmx: Really fix lazy FPU on nested guest") Reported-by:
Abhiroop Dabral <adabral@paloaltonetworks.com> Signed-off-by:
Peter Shier <pshier@google.com> Tested-by:
Liran Alon <liran.alon@oracle.com> Signed-off-by:
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Vitaly Kuznetsov authored
Using hypercall for sending IPIs is faster because this allows to specify any number of vCPUs (even > 64 with sparse CPU set), the whole procedure will take only one VMEXIT. Current Hyper-V TLFS (v5.0b) claims that HvCallSendSyntheticClusterIpi hypercall can't be 'fast' (passing parameters through registers) but apparently this is not true, Windows always uses it as 'fast' so we need to support that. Signed-off-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
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Vitaly Kuznetsov authored
VP inedx almost always matches VCPU and when it does it's faster to walk the sparse set instead of all vcpus. Signed-off-by:
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Vitaly Kuznetsov authored
This probably doesn't matter much (KVM_MAX_VCPUS is much lower nowadays) but valid_bank_mask is really u64 and not unsigned long. Signed-off-by:
Roman Kagan <rkagan@virtuozzo.com> Signed-off-by:
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Vitaly Kuznetsov authored
In most common cases VP index of a vcpu matches its vcpu index. Userspace is, however, free to set any mapping it wishes and we need to account for that when we need to find a vCPU with a particular VP index. To keep search algorithms optimal in both cases introduce 'num_mismatched_vp_indexes' counter showing how many vCPUs with mismatching VP index we have. In case the counter is zero we can assume vp_index == vcpu_idx. Signed-off-by:
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Vitaly Kuznetsov authored
Rename 'hv' to 'hv_vcpu' in kvm_hv_set_msr/kvm_hv_get_msr(); 'hv' is 'reserved' for 'struct kvm_hv' variables across the file. Signed-off-by:
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Vitaly Kuznetsov authored
We can use 'NULL' to represent 'all cpus' case in kvm_make_vcpus_request_mask() and avoid building vCPU mask with all vCPUs. Suggested-by:
Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:
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Vitaly Kuznetsov authored
Hyper-V TLFS (5.0b) states: > Virtual processors are identified by using an index (VP index). The > maximum number of virtual processors per partition supported by the > current implementation of the hypervisor can be obtained through CPUID > leaf 0x40000005. A virtual processor index must be less than the > maximum number of virtual processors per partition. Forbid userspace to set VP_INDEX above KVM_MAX_VCPUS. get_vcpu_by_vpidx() can now be optimized to bail early when supplied vpidx is >= KVM_MAX_VCPUS. Signed-off-by:
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Paolo Bonzini authored
If kvm_apic_map_get_dest_lapic() finds a disabled LAPIC, it will return with bitmap==0 and (*r == -1) will be returned to userspace. QEMU may then record "KVM: injection failed, MSI lost (Operation not permitted)" in its log, which is quite puzzling. Reported-by:
Peng Hao <penghao122@sina.com.cn> Signed-off-by:
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Wei Yang authored
Currently, there are two definitions related to huge page, but a little bit far from each other and seems loosely connected: * KVM_NR_PAGE_SIZES defines the number of different size a page could map * PT_MAX_HUGEPAGE_LEVEL means the maximum level of huge page The number of different size a page could map equals the maximum level of huge page, which is implied by current definition. While current implementation may not be kind to readers and further developers: * KVM_NR_PAGE_SIZES looks like a stand alone definition at first sight * in case we need to support more level, two places need to change This patch tries to make these two definition more close, so that reader and developer would feel more comfortable to manipulate. Signed-off-by:
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Tianyu Lan authored
is_external_interrupt() is not used now and so remove it. Signed-off-by:
Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by:
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Wei Yang authored
The code tries to pre-allocate *min* number of objects, so it is ok to return 0 when the kvm_mmu_memory_cache meets the requirement. Signed-off-by:
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Krish Sadhukhan authored
Suggested-by:
Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by:
Mark Kanda <mark.kanda@oracle.com> Reviewed-by:
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Wei Yang authored
On a 64bits machine, struct is naturally aligned with 8 bytes. Since kvm_mmu_page member *unsync* and *role* are less then 4 bytes, we can rearrange the sequence to compace the struct. As the comment shows, *role* and *gfn* are used to key the shadow page. In order to keep the comment valid, this patch moves the *unsync* up and exchange the position of *role* and *gfn*. From /proc/slabinfo, it shows the size of kvm_mmu_page is 8 bytes less and with one more object per slap after applying this patch. # name <active_objs> <num_objs> <objsize> <objperslab> kvm_mmu_page_header 0 0 168 24 kvm_mmu_page_header 0 0 160 25 Signed-off-by: -
Sean Christopherson authored
A VMEnter that VMFails (as opposed to VMExits) does not touch host state beyond registers that are explicitly noted in the VMFail path, e.g. EFLAGS. Host state does not need to be loaded because VMFail is only signaled for consistency checks that occur before the CPU starts to load guest state, i.e. there is no need to restore any state as nothing has been modified. But in the case where a VMFail is detected by hardware and not by KVM (due to deferring consistency checks to hardware), KVM has already loaded some amount of guest state. Luckily, "loaded" only means loaded to KVM's software model, i.e. vmcs01 has not been modified. So, unwind our software model to the pre-VMEntry host state. Not restoring host state in this VMFail path leads to a variety of failures because we end up with stale data in vcpu->arch, e.g. CR0, CR4, EFER, etc... will all be out of sync relative to vmcs01. Any significant delta in the stale data is all but guaranteed to crash L1, e.g. emulation of SMEP, SMAP, UMIP, WP, etc... will be wrong. An alternative to this "soft" reload would be to load host state from vmcs12 as if we triggered a VMExit (as opposed to VMFail), but that is wildly inconsistent with respect to the VMX architecture, e.g. an L1 VMM with separate VMExit and VMFail paths would explode. Note that this approach does not mean KVM is 100% accurate with respect to VMX hardware behavior, even at an architectural level (the exact order of consistency checks is microarchitecture specific). But 100% emulation accuracy isn't the goal (with this patch), rather the goal is to be consistent in the information delivered to L1, e.g. a VMExit should not fall-through VMENTER, and a VMFail should not jump to HOST_RIP. This technically reverts commit "5af41573 (KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure)", but retains the core aspects of that patch, just in an open coded form due to the need to pull state from vmcs01 instead of vmcs12. Restoring host state resolves a variety of issues introduced by commit "4f350c6d (kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly)", which remedied the incorrect behavior of treating VMFail like VMExit but in doing so neglected to restore arch state that had been modified prior to attempting nested VMEnter. A sample failure that occurs due to stale vcpu.arch state is a fault of some form while emulating an LGDT (due to emulated UMIP) from L1 after a failed VMEntry to L3, in this case when running the KVM unit test test_tpr_threshold_values in L1. L0 also hits a WARN in this case due to a stale arch.cr4.UMIP. L1: BUG: unable to handle kernel paging request at ffffc90000663b9e PGD 276512067 P4D 276512067 PUD 276513067 PMD 274efa067 PTE 8000000271de2163 Oops: 0009 [#1] SMP CPU: 5 PID: 12495 Comm: qemu-system-x86 Tainted: G W 4.18.0-rc2+ #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:native_load_gdt+0x0/0x10 ... Call Trace: load_fixmap_gdt+0x22/0x30 __vmx_load_host_state+0x10e/0x1c0 [kvm_intel] vmx_switch_vmcs+0x2d/0x50 [kvm_intel] nested_vmx_vmexit+0x222/0x9c0 [kvm_intel] vmx_handle_exit+0x246/0x15a0 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x850/0x1830 [kvm] kvm_vcpu_ioctl+0x3a1/0x5c0 [kvm] do_vfs_ioctl+0x9f/0x600 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x4f/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 L0: WARNING: CPU: 2 PID: 3529 at arch/x86/kvm/vmx.c:6618 handle_desc+0x28/0x30 [kvm_intel] ... CPU: 2 PID: 3529 Comm: qemu-system-x86 Not tainted 4.17.2-coffee+ #76 Hardware name: Intel Corporation Kabylake Client platform/KBL S RIP: 0010:handle_desc+0x28/0x30 [kvm_intel] ... Call Trace: kvm_arch_vcpu_ioctl_run+0x863/0x1840 [kvm] kvm_vcpu_ioctl+0x3a1/0x5c0 [kvm] do_vfs_ioctl+0x9f/0x5e0 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x49/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 5af41573 (KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure) Fixes: 4f350c6d (kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly) Cc: Jim Mattson <jmattson@google.com> Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmáÅ
™ <rkrcmar@redhat.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: -
Jim Mattson authored
According to volume 3 of the SDM, bits 63:15 and 12:4 of the exit qualification field for debug exceptions are reserved (cleared to 0). However, the SDM is incorrect about bit 16 (corresponding to DR6.RTM). This bit should be set if a debug exception (#DB) or a breakpoint exception (#BP) occurred inside an RTM region while advanced debugging of RTM transactional regions was enabled. Note that this is the opposite of DR6.RTM, which "indicates (when clear) that a debug exception (#DB) or breakpoint exception (#BP) occurred inside an RTM region while advanced debugging of RTM transactional regions was enabled." There is still an issue with stale DR6 bits potentially being misreported for the current debug exception. DR6 should not have been modified before vectoring the #DB exception, and the "new DR6 bits" should be available somewhere, but it was and they aren't. Fixes: b96fb439 ("KVM: nVMX: fixes to nested virt interrupt injection") Signed-off-by:
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Andrew Jones authored
Signed-off-by:
Andrew Jones <drjones@redhat.com> Signed-off-by:
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Andrew Jones authored
Let's add the 40 PA-bit versions of the VM modes, that AArch64 should have been using, so we can extend the dirty log test without breaking things. Signed-off-by:
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Andrew Jones authored
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Andrew Jones authored
While we're messing with the code for the port and to support guest page sizes that are less than the host page size, we also make some code formatting cleanups and apply sync_global_to_guest(). Signed-off-by:
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Andrew Jones authored
Rename VM_MODE_FLAT48PG to be more descriptive of its config and add a new config that has the same parameters, except with 64K pages. Signed-off-by:
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Andrew Jones authored
This code adds VM and VCPU setup code for the VM_MODE_FLAT48PG mode. The VM_MODE_FLAT48PG isn't yet fully supportable, as it defines the guest physical address limit as 52-bits, and KVM currently only supports guests with up to 40-bit physical addresses (see KVM_PHYS_SHIFT). VM_MODE_FLAT48PG will work fine, though, as long as no >= 40-bit physical addresses are used. Signed-off-by:
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Andrew Jones authored
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Andrew Jones authored
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Andrew Jones authored
Tidy up kvm-util code: code/comment formatting, remove unused code, and move x86 specific code out. We also move vcpu_dump() out of common code, because not all arches (AArch64) have KVM_GET_REGS. Signed-off-by:
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Andrew Jones authored
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Andrew Jones authored
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Andrew Jones authored
Rework the guest exit to userspace code to generalize the concept into what it is, a "hypercall to userspace", and provide two implementations of it: the PortIO version currently used, but only useable by x86, and an MMIO version that other architectures (except s390) can use. Signed-off-by:
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Andrew Jones authored
Guest code may want to call functions that have variable arguments. To do so, we either need to compile with -mno-sse or enable SSE in the VCPUs. As it should be pretty safe to turn on the feature, and -mno-sse would make linking test code with standard libraries difficult, we choose the feature enabling. Signed-off-by:
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Wanpeng Li authored
In cloud environment, lapic_timer_advance_ns is needed to be tuned for every CPU generations, and every host kernel versions(the kvm-unit-tests/tscdeadline_latency.flat is 5700 cycles for upstream kernel and 9600 cycles for our 3.10 product kernel, both preemption_timer=N, Skylake server). This patch adds the capability to automatically tune lapic_timer_advance_ns step by step, the initial value is 1000ns as 'commit d0659d94 ("KVM: x86: add option to advance tscdeadline hrtimer expiration")' recommended, it will be reduced when it is too early, and increased when it is too late. The guest_tsc and tsc_deadline are hard to equal, so we assume we are done when the delta is within a small scope e.g. 100 cycles. This patch reduces latency (kvm-unit-tests/tscdeadline_latency, busy waits, preemption_timer enabled) from ~2600 cyles to ~1200 cyles on our Skylake server. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Liran Alon <liran.alon@oracle.com> Signed-off-by:
Wanpeng Li <wanpengli@tencent.com> Signed-off-by:
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- 13 Oct, 2018 4 commits
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Liran Alon authored
If L1 uses VPID, it expects TLB to not be flushed on L1<->L2 transitions. However, code currently flushes TLB nonetheless if we didn't allocate a vpid02 for L2. As in this case, vmcs02->vpid == vmcs01->vpid == vmx->vpid. But, if L1 uses EPT, TLB entires populated by L2 are tagged with EPTP02 while TLB entries populated by L1 are tagged with EPTP01. Therefore, we can also avoid TLB flush if L1 uses VPID and EPT. Reviewed-by:
Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by:
Darren Kenny <darren.kenny@oracle.com> Reviewed-by:
Nikita Leshenko <nikita.leshchenko@oracle.com> Signed-off-by:
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Liran Alon authored
All VPID12s used on a given L1 vCPU is translated to a single VPID02 (vmx->nested.vpid02 or vmx->vpid). Therefore, on L1->L2 VMEntry, we need to invalidate linear and combined mappings tagged by VPID02 in case L1 uses VPID and vmcs12->vpid was changed since last L1->L2 VMEntry. However, current code invalidates the wrong mappings as it calls __vmx_flush_tlb() with invalidate_gpa parameter set to true which will result in invalidating combined and guest-physical mappings tagged with active EPTP which is EPTP01. Similarly, INVVPID emulation have the exact same issue. Fix both issues by just setting invalidate_gpa parameter to false which will result in invalidating linear and combined mappings tagged with given VPID02 as required. Reviewed-by:
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Liran Alon authored
In case L0 didn't allocate vmx->nested.vpid02 for L2, vmcs02->vpid is set to vmx->vpid. Consider this case when emulating L1 INVVPID in L0. Reviewed-by:
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Liran Alon authored
If L1 and L2 share VPID (because L1 don't use VPID or we haven't allocated a vpid02), we need to flush TLB on L1<->L2 transitions. Before this patch, this TLB flushing was done by vmx_flush_tlb(). If L0 use EPT, this will translate into INVEPT(active_eptp); However, if L1 use EPT, in L1->L2 VMEntry, active EPTP is EPTP01 but TLB entries populated by L2 are tagged with EPTP02. Therefore we should delay vmx_flush_tlb() until active_eptp is EPTP02. To achieve this, instead of directly calling vmx_flush_tlb() we request it to be called by KVM_REQ_TLB_FLUSH which is evaluated after KVM_REQ_LOAD_CR3 which sets the active_eptp to EPTP02 as required. Similarly, on L2->L1 VMExit, active EPTP is EPTP02 but TLB entries populated by L1 are tagged with EPTP01 and therefore we should delay vmx_flush_tlb() until active_eptp is EPTP01. Reviewed-by:
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