summaryrefslogtreecommitdiff
AgeCommit message (Collapse)AuthorFilesLines
2016-06-21KVM: s390: vsie: support 64-bit-SCAODavid Hildenbrand3-0/+7
Let's provide the 64-bit-SCAO facility to guest 2, so he can set up a SCA for guest 3 that has a 64 bit address. Please note that we already require the 64 bit SCAO for our vsie implementation, in order to forward the SCA directly (by pinning the page). Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support run-time-instrumentationDavid Hildenbrand1-0/+26
As soon as guest 2 is allowed to use run-time-instrumentation (indicated via via STFLE), it can also enable it for guest 3. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support vectory facility (SIMD)David Hildenbrand2-1/+32
As soon as guest 2 is allowed to use the vector facility (indicated via STFLE), it can also enable it for guest 3. We have to take care of the sattellite block that might be used when not relying on lazy vector copying (not the case for KVM). Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support transactional executionDavid Hildenbrand1-2/+35
As soon as guest 2 is allowed to use transactional execution (indicated via STFLE), he can also enable it for guest 3. Active transactional execution requires also the second prefix page to be mapped. If that page cannot be mapped, a validity icpt has to be presented to the guest. We have to take care of tx being toggled on/off, otherwise we might get wrong prefix validity icpt. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support aes dea wrapping keysDavid Hildenbrand1-1/+55
As soon as message-security-assist extension 3 is enabled for guest 2, we have to allow key wrapping for guest 3. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support STFLE interpretationDavid Hildenbrand1-2/+47
Issuing STFLE is extremely rare. Instead of copying 2k on every VSIE call, let's do this lazily, when a guest 3 tries to execute STFLE. We can setup the block and retry. Unfortunately, we can't directly forward that facility list, as we only have a 31 bit address for the facility list designation. So let's use a DMA allocation for our vsie_page instead for now. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support host-protection-interruptionDavid Hildenbrand1-0/+3
Introduced with ESOP, therefore available for the guest if it is allowed to use ESOP. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support edat1 / edat2David Hildenbrand1-0/+7
If guest 2 is allowed to use edat 1 / edat 2, it can also set it up for guest 3, so let's properly check and forward the edat cpuflags. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: support setting the ibcDavid Hildenbrand1-0/+21
As soon as we forward an ibc to guest 2 (indicated via kvm->arch.model.ibc), he can also use it for guest 3. Let's properly round the ibc up/down, so we avoid any potential validity icpts from the underlying SIE, if it doesn't simply round the values. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: optimize gmap prefix mappingDavid Hildenbrand1-2/+29
In order to not always map the prefix, we have to take care of certain aspects that implicitly unmap the prefix: - Changes to the prefix address - Changes to MSO, because the HVA of the prefix is changed - Changes of the gmap shadow (e.g. unshadowed, asce or edat changes) By properly handling these cases, we can stop remapping the prefix when there is no reason to do so. This also allows us now to not acquire any gmap shadow locks when rerunning the vsie and still having a valid gmap shadow. Please note, to detect changing gmap shadows, we have to keep the reference of the gmap shadow. The address of a gmap shadow does otherwise not reliably indicate if the gmap shadow has changed (the memory chunk could get reused). Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21KVM: s390: vsie: initial support for nested virtualizationDavid Hildenbrand7-2/+794
This patch adds basic support for nested virtualization on s390x, called VSIE (virtual SIE) and allows it to be used by the guest if the necessary facilities are supported by the hardware and enabled for the guest. In order to make this work, we have to shadow the sie control block provided by guest 2. In order to gain some performance, we have to reuse the same shadow blocks as good as possible. For now, we allow as many shadow blocks as we have VCPUs (that way, every VCPU can run the VSIE concurrently). We have to watch out for the prefix getting unmapped out of our shadow gmap and properly get the VCPU out of VSIE in that case, to fault the prefix pages back in. We use the PROG_REQUEST bit for that purpose. This patch is based on an initial prototype by Tobias Elpelt. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-21mm/page_ref: introduce page_ref_inc_returnDavid Hildenbrand1-0/+9
Let's introduce that helper. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390: introduce page_to_virt() and pfn_to_virt()David Hildenbrand1-0/+2
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20KVM: s390: backup the currently enabled gmap when scheduled outDavid Hildenbrand4-3/+19
Nested virtualization will have to enable own gmaps. Current code would enable the wrong gmap whenever scheduled out and back in, therefore resulting in the wrong gmap being enabled. This patch reenables the last enabled gmap, therefore avoiding having to touch vcpu->arch.gmap when enabling a different gmap. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20KVM: s390: fast path for shadow gmaps in gmap notifierDavid Hildenbrand1-0/+2
The default kvm gmap notifier doesn't have to handle shadow gmaps. So let's just directly exit in case we get notified about one. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: don't fault everything in read-write in gmap_pte_op_fixup()David Hildenbrand1-6/+11
Let's not fault in everything in read-write but limit it to read-only where possible. When restricting access rights, we already have the required protection level in our hands. When reading from guest 2 storage (gmap_read_table), it is obviously PROT_READ. When shadowing a pte, the required protection level is given via the guest 2 provided pte. Based on an initial patch by Martin Schwidefsky. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: allow to check if a gmap shadow is validDavid Hildenbrand2-0/+21
It will be very helpful to have a mechanism to check without any locks if a given gmap shadow is still valid and matches the given properties. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: remember the int code for the last gmap faultDavid Hildenbrand2-0/+2
For nested virtualization, we want to know if we are handling a protection exception, because these can directly be forwarded to the guest without additional checks. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: limit number of real-space gmap shadowsDavid Hildenbrand1-0/+13
We have no known user of real-space designation and only support it to be architecture compliant. Gmap shadows with real-space designation are never unshadowed automatically, as there is nothing to protect for the top level table. So let's simply limit the number of such shadows to one by removing existing ones on creation of another one. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: support real-space for gmap shadowsDavid Hildenbrand3-10/+65
We can easily support real-space designation just like EDAT1 and EDAT2. So guest2 can provide for guest3 an asce with the real-space control being set. We simply have to allocate the biggest page table possible and fake all levels. There is no protection to consider. If we exceed guest memory, vsie code will inject an addressing exception (via program intercept). In the future, we could limit the fake table level to the gmap page table. As the top level page table can never go away, such gmap shadows will never get unshadowed, we'll have to come up with another way to limit the number of kept gmap shadows. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: push rte protection down to shadow pteDavid Hildenbrand1-7/+12
Just like we already do with ste protection, let's take rte protection into account. This way, the host pte doesn't have to be mapped writable. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: support EDAT2 for gmap shadowsDavid Hildenbrand3-5/+34
If the guest is enabled for EDAT2, we can easily create shadows for guest2 -> guest3 provided tables that make use of EDAT2. If guest2 references a 2GB page, this memory looks consecutive for guest2, but it does not have to be so for us. Therefore we have to create fake segment and page tables. This works just like EDAT1 support, so page tables are removed when the parent table (r3t table entry) is changed. We don't hve to care about: - ACCF-Validity Control in RTTE - Access-Control Bits in RTTE - Fetch-Protection Bit in RTTE - Common-Region Bit in RTTE Just like for EDAT1, all bits might be dropped and there is no guaranteed that they are active. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: support EDAT1 for gmap shadowsDavid Hildenbrand3-13/+55
If the guest is enabled for EDAT1, we can easily create shadows for guest2 -> guest3 provided tables that make use of EDAT1. If guest2 references a 1MB page, this memory looks consecutive for guest2, but it might not be so for us. Therefore we have to create fake page tables. We can easily add that to our existing infrastructure. The invalidation mechanism will make sure that fake page tables are removed when the parent table (sgt table entry) is changed. As EDAT1 also introduced protection on all page table levels, we have to also shadow these correctly. We don't have to care about: - ACCF-Validity Control in STE - Access-Control Bits in STE - Fetch-Protection Bit in STE - Common-Segment Bit in STE As all bits might be dropped and there is no guaranteed that they are active ("unpredictable whether the CPU uses these bits", "may be used"). Without using EDAT1 in the shadow ourselfes (STE-format control == 0), simply shadowing these bits would not be enough. They would be ignored. Please note that we are using the "fake" flag to make this look consistent with further changes (EDAT2, real-space designation support) and don't let the shadow functions handle fc=1 stes. In the future, with huge pages in the host, gmap_shadow_pgt() could simply try to map a huge host page if "fake" is set to one and indicate via return value that no lower fake tables / shadow ptes are required. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: prepare for EDAT1/EDAT2 support in gmap shadowDavid Hildenbrand2-6/+15
In preparation for EDAT1/EDAT2 support for gmap shadows, we have to store the requested edat level in the gmap shadow. The edat level used during shadow translation is a property of the gmap shadow. Depending on that level, the gmap shadow will look differently for the same guest tables. We have to store it internally in order to support it later. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: push ste protection down to shadow pteDavid Hildenbrand1-0/+1
If a guest ste is read-only, it doesn't make sense to force the ptes in as writable in the host. If the source page is read-only in the host, it won't have to be made writable. Please note that if the source page is not available, it will still be faulted in writable. This can be changed internally later on. If ste protection is removed, underlying shadow tables are also removed, therefore this change does not affect the guest. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: take ipte_lock during shadow faultsDavid Hildenbrand2-2/+12
Let's take the ipte_lock while working on guest 2 provided page table, just like the other gaccess functions. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: protection exceptions are corrrectly shadowedDavid Hildenbrand2-6/+2
As gmap shadows contains correct protection permissions, protection exceptons can directly be forwarded to guest 3. If we would encounter a protection exception while faulting, the next guest 3 run will automatically handle that for us. Keep the dat_protection logic in place, as it will be helpful later. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: take the mmap_sem in kvm_s390_shadow_fault()David Hildenbrand1-17/+15
Instead of doing it in the caller, let's just take the mmap_sem in kvm_s390_shadow_fault(). By taking it as read, we allow parallel faulting on shadow page tables, gmap shadow code is prepared for that. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: fix races on gmap_shadow creationDavid Hildenbrand2-17/+30
Before any thread is allowed to use a gmap_shadow, it has to be fully initialized. However, for invalidation to work properly, we have to register the new gmap_shadow before we protect the parent gmap table. Because locking is tricky, and we have to avoid duplicate gmaps, let's introduce an initialized field, that signalizes other threads if that gmap_shadow can already be used or if they have to retry. Let's properly return errors using ERR_PTR() instead of simply returning NULL, so a caller can properly react on the error. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: avoid races on region/segment/page table shadowingDavid Hildenbrand1-27/+70
We have to unlock sg->guest_table_lock in order to call gmap_protect_rmap(). If we sleep just before that call, another VCPU might pick up that shadowed page table (while it is not protected yet) and use it. In order to avoid these races, we have to introduce a third state - "origin set but still invalid" for an entry. This way, we can avoid another thread already using the entry before the table is fully protected. As soon as everything is set up, we can clear the invalid bit - if we had no race with the unshadowing code. Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: shadow pages with real guest requested protectionDavid Hildenbrand5-20/+15
We really want to avoid manually handling protection for nested virtualization. By shadowing pages with the protection the guest asked us for, the SIE can handle most protection-related actions for us (e.g. special handling for MVPG) and we can directly forward protection exceptions to the guest. PTEs will now always be shadowed with the correct _PAGE_PROTECT flag. Unshadowing will take care of any guest changes to the parent PTE and any host changes to the host PTE. If the host PTE doesn't have the fitting access rights or is not available, we have to fix it up. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: flush tlb of shadows in all situationsDavid Hildenbrand1-3/+4
For now, the tlb of shadow gmap is only flushed when the parent is removed, not when it is removed upfront. Therefore other shadow gmaps can reuse the tables without the tlb getting flushed. Fix this by simply flushing the tlb 1. Before the shadow tables are removed (analogouos to other unshadow functions) 2. When the gmap is freed and therefore the top level pages are freed. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: add kvm shadow fault functionMartin Schwidefsky2-0/+170
This patch introduces function kvm_s390_shadow_fault() used to resolve a fault on a shadow gmap. This function will do validity checking and build up the shadow page table hierarchy in order to fault in the requested page into the shadow page table structure. If an exception occurs while shadowing, guest 2 has to be notified about it using either an exception or a program interrupt intercept. If concurrent unshadowing occurres, this function will simply return with -EAGAIN and the caller has to retry. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: add shadow gmap supportMartin Schwidefsky8-34/+1262
For a nested KVM guest the outer KVM host needs to create shadow page tables for the nested guest. This patch adds the basic support to the guest address space (gmap) code. For each guest address space the inner KVM host creates, the first outer KVM host needs to create shadow page tables. The address space is identified by the ASCE loaded into the control register 1 at the time the inner SIE instruction for the second nested KVM guest is executed. The outer KVM host creates the shadow tables starting with the table identified by the ASCE on a on-demand basis. The outer KVM host will get repeated faults for all the shadow tables needed to run the second KVM guest. While a shadow page table for the second KVM guest is active the access to the origin region, segment and page tables needs to be restricted for the first KVM guest. For region and segment and page tables the first KVM guest may read the memory, but write attempt has to lead to an unshadow. This is done using the page invalid and read-only bits in the page table of the first KVM guest. If the first guest re-accesses one of the origin pages of a shadow, it gets a fault and the affected parts of the shadow page table hierarchy needs to be removed again. PGSTE tables don't have to be shadowed, as all interpretation assist can't deal with the invalid bits in the shadow pte being set differently than the original ones provided by the first KVM guest. Many bug fixes and improvements by David Hildenbrand. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: add reference counter to gmap structureMartin Schwidefsky3-30/+85
Let's use a reference counter mechanism to control the lifetime of gmap structures. This will be needed for further changes related to gmap shadows. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: extended gmap pte notifierMartin Schwidefsky5-55/+193
The current gmap pte notifier forces a pte into to a read-write state. If the pte is invalidated the gmap notifier is called to inform KVM that the mapping will go away. Extend this approach to allow read-write, read-only and no-access as possible target states and call the pte notifier for any change to the pte. This mechanism is used to temporarily set specific access rights for a pte without doing the heavy work of a true mprotect call. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/mm: use RCU for gmap notifier list and the per-mm gmap listMartin Schwidefsky5-29/+41
The gmap notifier list and the gmap list in the mm_struct change rarely. Use RCU to optimize the reader of these lists. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20s390/kvm: page table invalidation notifierMartin Schwidefsky3-9/+31
Pass an address range to the page table invalidation notifier for KVM. This allows to notify changes that affect a larger virtual memory area, e.g. for 1MB pages. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-16kvm: vmx: hook preemption timer supportYunhong Jiang3-2/+183
Hook the VMX preemption timer to the "hv timer" functionality added by the previous patch. This includes: checking if the feature is supported, if the feature is broken on the CPU, the hooks to setup/clean the VMX preemption timer, arming the timer on vmentry and handling the vmexit. A module parameter states if the VMX preemption timer should be utilized. Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> [Move hv_deadline_tsc to struct vcpu_vmx, use -1 as the "unset" value. Put all VMX bits here. Enable it by default #yolo. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16kvm: vmx: rename vmx_pre/post_block to pi_pre/post_blockYunhong Jiang1-2/+15
Prepare to switch from preemption timer to hrtimer in the vmx_pre/post_block. Current functions are only for posted interrupt, rename them accordingly. Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16KVM: x86: support using the vmx preemption timer for tsc deadline timerYunhong Jiang5-1/+100
The VMX preemption timer can be used to virtualize the TSC deadline timer. The VMX preemption timer is armed when the vCPU is running, and a VMExit will happen if the virtual TSC deadline timer expires. When the vCPU thread is blocked because of HLT, KVM will switch to use an hrtimer, and then go back to the VMX preemption timer when the vCPU thread is unblocked. This solution avoids the complex OS's hrtimer system, and the host timer interrupt handling cost, replacing them with a little math (for guest->host TSC and host TSC->preemption timer conversion) and a cheaper VMexit. This benefits latency for isolated pCPUs. [A word about performance... Yunhong reported a 30% reduction in average latency from cyclictest. I made a similar test with tscdeadline_latency from kvm-unit-tests, and measured - ~20 clock cycles loss (out of ~3200, so less than 1% but still statistically significant) in the worst case where the test halts just after programming the TSC deadline timer - ~800 clock cycles gain (25% reduction in latency) in the best case where the test busy waits. I removed the VMX bits from Yunhong's patch, to concentrate them in the next patch - Paolo] Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16kvm: lapic: separate start_sw_tscdeadline from start_apic_timerYunhong Jiang1-26/+31
The function to start the tsc deadline timer virtualization will be used also by the pre_block hook when we use the preemption timer; change it to a separate function. No logic changes. Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16KVM: s390: use kvm->created_vcpusPaolo Bonzini1-5/+5
The new created_vcpus field avoids possible races between enabling capabilities and creating VCPUs. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16KVM: remove kvm_vcpu_compatiblePaolo Bonzini5-22/+3
The new created_vcpus field makes it possible to avoid the race between irqchip and VCPU creation in a much nicer way; just check under kvm->lock whether a VCPU has already been created. We can then remove KVM_APIC_ARCHITECTURE too, because at this point the symbol is only governing the default definition of kvm_vcpu_compatible. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16KVM: introduce kvm->created_vcpusPaolo Bonzini2-6/+25
The race between creating the irqchip and the first VCPU is currently fixed by checking the presence of an irqchip before updating kvm->online_vcpus, and undoing the whole VCPU creation if someone created the irqchip in the meanwhile. Instead, introduce a new field in struct kvm that will count VCPUs under a mutex, without the atomic access and memory ordering that we need elsewhere to protect the vcpus array. This also plugs the race and is more easily applicable in all similar circumstances. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16x86/kvm/svm: Simplify cpu_has_svm()Borislav Petkov2-7/+2
Use already cached CPUID information instead of querying CPUID again. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Joerg Roedel <joro@8bytes.org> Cc: kvm@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: KVM: Use mipsregs.h defs for config registersJames Hogan2-72/+3
Convert MIPS KVM guest register state initialisation to use the standard <asm/mipsregs.h> register field definitions for Config registers, and drop the custom definitions in kvm_host.h which it was using before. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: KVM: Report more accurate CP0_Config fields to guestJames Hogan1-5/+15
Initialise the guest's CP0_Config register with a few more bits of information from the host. The BE bit should be set on big endian machines, the VI bit should be set on machines with a virtually tagged instruction cache, and the reported architecture revision should match that of the host (since we won't support emulating pre-r6 instruction encodings on r6 or vice versa). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: Add define for Config.VI (virtual icache) bitJames Hogan2-1/+2
The Config.VI bit specifies that the instruction cache is virtually tagged, which is checked in c-r4k.c's probe_pcache(). Add a proper definition for it in mipsregs.h and make use of it. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: KVM: Use host CCA for TLB mappingsJames Hogan2-9/+12
KVM TLB mappings for the guest were being created with a cache coherency attribute (CCA) of 3, which is cached incoherent. Create them instead with the default host CCA, which should be the correct one for coherency on SMP systems. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 14:20:53 +0000