- 06 Aug, 2018 40 commits
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Junaid Shahid authored
Adds support for storing multiple previous CR3/root_hpa pairs maintained as an LRU cache, so that the lockless CR3 switch path can be used when switching back to any of them. Signed-off-by:
Junaid Shahid <junaids@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Junaid Shahid authored
This needs a minor bug fix. The updated patch is as follows. Thanks, Junaid ------------------------------------------------------------------------------ kvm_mmu_invlpg() and kvm_mmu_invpcid_gva() only need to flush the TLB entries for the specific guest virtual address, instead of flushing all TLB entries associated with the VM. Signed-off-by:
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Junaid Shahid authored
When the guest indicates that the TLB doesn't need to be flushed in a CR3 switch, we can also skip resyncing the shadow page tables since an out-of-sync shadow page table is equivalent to an out-of-sync TLB. Signed-off-by:
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Junaid Shahid authored
kvm_mmu_free_roots() now takes a mask specifying which roots to free, so that either one of the roots (active/previous) can be individually freed when needed. Signed-off-by:
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Junaid Shahid authored
This allows invlpg() to be called using either the active root_hpa or the prev_root_hpa. Signed-off-by:
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Junaid Shahid authored
When PCIDs are enabled, the MSb of the source operand for a MOV-to-CR3 instruction indicates that the TLB doesn't need to be flushed. This change enables this optimization for MOV-to-CR3s in the guest that have been intercepted by KVM for shadow paging and are handled within the fast CR3 switch path. Signed-off-by:
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Junaid Shahid authored
Implement support for INVPCID in shadow paging mode as well. Signed-off-by:
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Junaid Shahid authored
When using shadow paging mode, propagate the guest's PCID value to the shadow CR3 in the host instead of always using PCID 0. Signed-off-by:
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Junaid Shahid authored
Remove the implicit flush from the set_cr3 handlers, so that the callers are able to decide whether to flush the TLB or not. Signed-off-by:
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Junaid Shahid authored
Use the fast CR3 switch mechanism to locklessly change the MMU root page when switching between L1 and L2. The switch from L2 to L1 should always go through the fast path, while the switch from L1 to L2 should go through the fast path if L1's CR3/EPTP for L2 hasn't changed since the last time. Signed-off-by:
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Junaid Shahid authored
This adds support for re-initializing the MMU context in a different mode while preserving the active root_hpa and the prev_root. Signed-off-by:
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Junaid Shahid authored
This generalizes the lockless CR3 switch path to be able to work across different MMU modes (e.g. nested vs non-nested) by checking that the expected page role of the new root page matches the page role of the previously stored root page in addition to checking that the new CR3 matches the previous CR3. Furthermore, instead of loading the hardware CR3 in fast_cr3_switch(), it is now done in vcpu_enter_guest(), as by that time the MMU context would be up-to-date with the VCPU mode. Signed-off-by:
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Junaid Shahid authored
The KVM_REQ_LOAD_CR3 request loads the hardware CR3 using the current root_hpa. Signed-off-by:
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Junaid Shahid authored
These functions factor out the base role calculation from the corresponding kvm_init_*_mmu() functions. The new functions return what would be the role assigned to a root page in the current VCPU state. This can be masked with mmu_base_role_mask to derive the base role. Signed-off-by:
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Junaid Shahid authored
When using shadow paging, a CR3 switch in the guest results in a VM Exit. In the common case, that VM exit doesn't require much processing by KVM. However, it does acquire the MMU lock, which can start showing signs of contention under some workloads even on a 2 VCPU VM when the guest is using KPTI. Therefore, we add a fast path that avoids acquiring the MMU lock in the most common cases e.g. when switching back and forth between the kernel and user mode CR3s used by KPTI with no guest page table changes in between. For now, this fast path is implemented only for 64-bit guests and hosts to avoid the handling of PDPTEs, but it can be extended later to 32-bit guests and/or hosts as well. Signed-off-by:
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Junaid Shahid authored
kvm_mmu_sync_roots() can locklessly check whether a sync is needed and just bail out if it isn't. Signed-off-by:
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Junaid Shahid authored
sync_page() calls set_spte() from a loop across a page table. It would work better if set_spte() left the TLB flushing to its callers, so that sync_page() can aggregate into a single call. Signed-off-by:
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Peter Xu authored
It's never used. Drop it. Signed-off-by:
Peter Xu <peterx@redhat.com> Signed-off-by:
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Liran Alon authored
No functionality change. This is done as a preparation for VMCS shadowing virtualization. Signed-off-by:
Liran Alon <liran.alon@oracle.com> Signed-off-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
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Liran Alon authored
No functionality change. Signed-off-by:
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Liran Alon authored
Expose VMCS shadowing to L1 as a VMX capability of the virtual CPU, whether or not VMCS shadowing is supported by the physical CPU. (VMCS shadowing emulation) Shadowed VMREADs and VMWRITEs from L2 are handled by L0, without a VM-exit to L1. Signed-off-by:
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Liran Alon authored
KVM: nVMX: Do not forward VMREAD/VMWRITE VMExits to L1 if required so by vmcs12 vmread/vmwrite bitmaps This is done as a preparation for VMCS shadowing emulation. Signed-off-by:
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Liran Alon authored
This is done as a preparation to VMCS shadowing emulation. Signed-off-by:
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Paolo Bonzini authored
This includes setting up the shadow VMCS and the secondary execution controls in lib/vmx.c. Signed-off-by: -
Paolo Bonzini authored
The shadow vmcs12 cannot be flushed on KVM_GET_NESTED_STATE, because at that point guest memory is assumed by userspace to be immutable. Capture the cache in vmx_get_nested_state, adding another page at the end if there is an active shadow vmcs12. Signed-off-by: -
Liran Alon authored
This is done is done as a preparation to VMCS shadowing emulation. Signed-off-by:
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Liran Alon authored
Intel SDM considers these checks to be part of "Checks on Guest Non-Register State". Note that it is legal for vmcs->vmcs_link_pointer to be -1ull when VMCS shadowing is enabled. In this case, any VMREAD/VMWRITE to shadowed-field sets the ALU flags for VMfailInvalid (i.e. CF=1). Signed-off-by:
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Liran Alon authored
Signed-off-by:
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Liran Alon authored
Signed-off-by:
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Liran Alon authored
Signed-off-by:
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Liran Alon authored
Signed-off-by:
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Liran Alon authored
No functionality change. This is done as a preparation for VMCS shadowing emulation. Signed-off-by:
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Liran Alon authored
No functionality change. Signed-off-by:
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Paolo Bonzini authored
Signed-off-by: -
Jim Mattson authored
For nested virtualization L0 KVM is managing a bit of state for L2 guests, this state can not be captured through the currently available IOCTLs. In fact the state captured through all of these IOCTLs is usually a mix of L1 and L2 state. It is also dependent on whether the L2 guest was running at the moment when the process was interrupted to save its state. With this capability, there are two new vcpu ioctls: KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE. These can be used for saving and restoring a VM that is in VMX operation. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by:
KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by:
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Paolo Bonzini authored
If the vCPU enters system management mode while running a nested guest, RSM starts processing the vmentry while still in SMM. In that case, however, the pages pointed to by the vmcs12 might be incorrectly loaded from SMRAM. To avoid this, delay the handling of the pages until just before the next vmentry. This is done with a new request and a new entry in kvm_x86_ops, which we will be able to reuse for nested VMX state migration. Extracted from a patch by Jim Mattson and KarimAllah Ahmed. Signed-off-by: -
Paolo Bonzini authored
The test calls KVM_RUN repeatedly, and creates an entirely new VM with the old memory and vCPU state on every exit to userspace. The kvm_util API is expanded with two functions that manage the lifetime of a kvm_vm struct: the first closes the file descriptors and leaves the memory allocated, and the second opens the file descriptors and reuses the memory from the previous incarnation of the kvm_vm struct. For now the test is very basic, as it does not test for example XSAVE or vCPU events. However, it will test nested virtualization state starting with the next patch. Signed-off-by: -
Paolo Bonzini authored
The selftests were not munmap-ing the kvm_run area from the vcpu file descriptor. The result was that kvm_vcpu_release was not called and a reference was left in the parent "struct kvm". Ultimately this was visible in the upcoming state save/restore test as an error when KVM attempted to create a duplicate debugfs entry. Signed-off-by: -
Paolo Bonzini authored
The allocation of the VMXON and VMCS is currently done twice, in lib/vmx.c and in vmx_tsc_adjust_test.c. Reorganize the code to provide a cleaner and easier to use API to the tests. lib/vmx.c now does the complete setup of the VMX data structures, but does not create the VM or set CPUID. This has to be done by the caller. Signed-off-by: -
Paolo Bonzini authored
The GDT and the TSS base were left to zero, and this has interesting effects when the TSS descriptor is later read to set up a VMCS's TR_BASE. Basically it worked by chance, and this patch fixes it by setting up all the protected mode data structures properly. Because the GDT and TSS addresses are virtual, the page tables now always exist at the time of vcpu setup. Signed-off-by:
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