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2022-07-19KVM: s390: pv: don't present the ecall interrupt twiceNico Boehr
When the SIGP interpretation facility is present and a VCPU sends an ecall to another VCPU in enabled wait, the sending VCPU receives a 56 intercept (partial execution), so KVM can wake up the receiving CPU. Note that the SIGP interpretation facility will take care of the interrupt delivery and KVM's only job is to wake the receiving VCPU. For PV, the sending VCPU will receive a 108 intercept (pv notify) and should continue like in the non-PV case, i.e. wake the receiving VCPU. For PV and non-PV guests the interrupt delivery will occur through the SIGP interpretation facility on SIE entry when SIE finds the X bit in the status field set. However, in handle_pv_notification(), there was no special handling for SIGP, which leads to interrupt injection being requested by KVM for the next SIE entry. This results in the interrupt being delivered twice: once by the SIGP interpretation facility and once by KVM through the IICTL. Add the necessary special handling in handle_pv_notification(), similar to handle_partial_execution(), which simply wakes the receiving VCPU and leave interrupt delivery to the SIGP interpretation facility. In contrast to external calls, emergency calls are not interpreted but also cause a 108 intercept, which is why we still need to call handle_instruction() for SIGP orders other than ecall. Since kvm_s390_handle_sigp_pei() is now called for all SIGP orders which cause a 108 intercept - even if they are actually handled by handle_instruction() - move the tracepoint in kvm_s390_handle_sigp_pei() to avoid possibly confusing trace messages. Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Cc: <stable@vger.kernel.org> # 5.7 Fixes: da24a0cc58ed ("KVM: s390: protvirt: Instruction emulation") Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220718130434.73302-1-nrb@linux.ibm.com Message-Id: <20220718130434.73302-1-nrb@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2022-02-14KVM: s390: Honor storage keys when accessing guest memoryJanis Schoetterl-Glausch
Storage key checking had not been implemented for instructions emulated by KVM. Implement it by enhancing the functions used for guest access, in particular those making use of access_guest which has been renamed to access_guest_with_key. Accesses via access_guest_real should not be key checked. For actual accesses, key checking is done by copy_from/to_user_key (which internally uses MVCOS/MVCP/MVCS). In cases where accessibility is checked without an actual access, this is performed by getting the storage key and checking if the access key matches. In both cases, if applicable, storage and fetch protection override are honored. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220211182215.2730017-3-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2021-10-25KVM: s390: pv: avoid stalls when making pages secureClaudio Imbrenda
Improve make_secure_pte to avoid stalls when the system is heavily overcommitted. This was especially problematic in kvm_s390_pv_unpack, because of the loop over all pages that needed unpacking. Due to the locks being held, it was not possible to simply replace uv_call with uv_call_sched. A more complex approach was needed, in which uv_call is replaced with __uv_call, which does not loop. When the UVC needs to be executed again, -EAGAIN is returned, and the caller (or its caller) will try again. When -EAGAIN is returned, the path is the same as when the page is in writeback (and the writeback check is also performed, which is harmless). Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests") Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20210920132502.36111-5-imbrenda@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-09-28KVM: s390: Function documentation fixesJanosch Frank
The latest compile changes pointed us to a few instances where we use the kernel documentation style but don't explain all variables or don't adhere to it 100%. It's easy to fix so let's do that. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-12-10KVM: s390: Add memcg accounting to KVM allocationsChristian Borntraeger
Almost all kvm allocations in the s390x KVM code can be attributed to the process that triggers the allocation (in other words, no global allocation for other guests). This will help the memcg controller to make the right decisions. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com>
2020-03-16Merge tag 'kvm-s390-next-5.7-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Features and Enhancements for 5.7 part1 1. Allow to disable gisa 2. protected virtual machines Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state like guest memory and guest registers anymore. Instead the PVMs are mostly managed by a new entity called Ultravisor (UV), which provides an API, so KVM and the PV can request management actions. PVMs are encrypted at rest and protected from hypervisor access while running. They switch from a normal operation into protected mode, so we can still use the standard boot process to load a encrypted blob and then move it into protected mode. Rebooting is only possible by passing through the unprotected/normal mode and switching to protected again. One mm related patch will go via Andrews mm tree ( mm/gup/writeback: add callbacks for inaccessible pages)
2020-03-16KVM: Remove unnecessary asm/kvm_host.h includesPeter Xu
Remove includes of asm/kvm_host.h from files that already include linux/kvm_host.h to make it more obvious that there is no ordering issue between the two headers. linux/kvm_host.h includes asm/kvm_host.h to pick up architecture specific settings, and this will never change, i.e. including asm/kvm_host.h after linux/kvm_host.h may seem problematic, but in practice is simply redundant. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-27KVM: s390: protvirt: Report CPU state to UltravisorJanosch Frank
VCPU states have to be reported to the ultravisor for SIGP interpretation, kdump, kexec and reboot. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Write sthyi data to instruction data areaJanosch Frank
STHYI data has to go through the bounce buffer. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390/mm: handle guest unpin eventsClaudio Imbrenda
The current code tries to first pin shared pages, if that fails (e.g. because the page is not shared) it will export them. For shared pages this means that we get a new intercept telling us that the guest is unsharing that page. We will unpin the page at that point in time, following the same rules as for making a page secure (i.e. waiting for writeback, no elevated page references, etc.) Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: handle secure guest prefix pagesJanosch Frank
The SPX instruction is handled by the ultravisor. We do get a notification intercept, though. Let us update our internal view. In addition to that, when the guest prefix page is not secure, an intercept 112 (0x70) is indicated. Let us make the prefix pages secure again. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Handle spec exception loopsJanosch Frank
SIE intercept code 8 is used only on exception loops for protected guests. That means we need to stop the guest when we see it. This is done by userspace. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Add SCLP interrupt handlingChristian Borntraeger
The sclp interrupt is kind of special. The ultravisor polices that we do not inject an sclp interrupt with payload if no sccb is outstanding. On the other hand we have "asynchronous" event interrupts, e.g. for console input. We separate both variants into sclp interrupt and sclp event interrupt. The sclp interrupt is masked until a previous servc instruction has finished (sie exit 108). [frankja@linux.ibm.com: factoring out write_sclp] Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Instruction emulationJanosch Frank
We have two new SIE exit codes dealing with instructions. 104 (0x68) for a secure instruction interception, on which the SIE needs hypervisor action to complete the instruction. We can piggy-back on the existing instruction handlers. 108 which is merely a notification and provides data for tracking and management. For example this is used to tell the host about a new value for the prefix register. As there will be several special case handlers in later patches, we handle this in a separate function. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: Handle SE notification interceptionsJanosch Frank
Since there is no interception for load control and load psw instruction in the protected mode, we need a new way to get notified whenever we can inject an IRQ right after the guest has just enabled the possibility for receiving them. The new interception codes solve that problem by providing a notification for changes to IRQ enablement relevant bits in CRs 0, 6 and 14, as well a the machine check mask bit in the PSW. No special handling is needed for these interception codes, the KVM pre-run code will consult all necessary CRs and PSW bits and inject IRQs the guest is enabled for. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-14KVM: s390: add exit io request stats and simplify codeChristian Borntraeger
We want to count IO exit requests in kvm_stat. At the same time we can get rid of the handle_noop function. Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-02-14KVM: s390: use switch vs jump table in intercept.cChristian Borntraeger
Instead of having huge jump tables for function selection, let's use normal switch/case statements for the instruction handlers in intercept.c We can now also get rid of intercept_handler_t. This allows the compiler to make the right decision depending on the situation (e.g. avoid jump-tables for thunks). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-12-06KVM: s390: Remove redundant license textGreg Kroah-Hartman
Now that the SPDX tag is in all arch/s390/kvm/ files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Message-Id: <20171124140043.10062-9-gregkh@linuxfoundation.org> Acked-by: Cornelia Huck <cohuck@redhat.com> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-12-06KVM: s390: add SPDX identifiers to the remaining filesGreg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kvm/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Message-Id: <20171124140043.10062-3-gregkh@linuxfoundation.org> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-10-09s390/sthyi: add cache to store hypervisor infoQingFeng Hao
STHYI requires extensive locking in the higher hypervisors and is very computational/memory expensive. Therefore we cache the retrieved hypervisor info whose valid period is 1s with mutex to allow concurrent access. rw semaphore can't benefit here due to cache line bounce. Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-10-09s390/sthyi: reorganize sthyi implementationQingFeng Hao
As we need to support sthyi instruction on LPAR too, move the common code to kernel part and kvm related code to intercept.c for better reuse. Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-04-21KVM: s390: Support keyless subset guest modeFarhan Ali
If the KSS facility is available on the machine, we also make it available for our KVM guests. The KSS facility bypasses storage key management as long as the guest does not issue a related instruction. When that happens, the control is returned to the host, which has to turn off KSS for a guest vcpu before retrying the instruction. Signed-off-by: Corey S. McQuay <csmcquay@linux.vnet.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-03-22KVM: s390: gs support for kvm guestsFan Zhang
This patch adds guarded storage support for KVM guest. We need to setup the necessary control blocks, the kvm_run structure for the new registers, the necessary wrappers for VSIE, as well as the machine check save areas. GS is enabled lazily and the register saving and reloading is done in KVM code. As this feature adds new content for migration, we provide a new capability for enablement (KVM_CAP_S390_GS). Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-03-21KVM: s390: Use defines for intercept codeFarhan Ali
Let's use #define values for better readability. Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-03-16KVM: s390: Handle sthyi also for instruction interceptChristian Borntraeger
Right now we handle the STHYI only via the operation exception intercept (illegal instruction). If hardware ever decides to provide an instruction intercept for STHYI, we should handle that as well. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-02-06KVM: s390: detect some program check loopsChristian Borntraeger
Sometimes (e.g. early boot) a guest is broken in such ways that it loops 100% delivering operation exceptions (illegal operation) but the pgm new PSW is not set properly. This will result in code being read from address zero, which usually contains another illegal op. Let's detect this case and return to userspace. Instead of only detecting this for address zero apply a heuristic that will work for any program check new psw. We do not want guest problem state to be able to trigger a guest panic, e.g. by faulting on an address that is the same as the program check new PSW, so we check for the problem state bit being off. With proper handling in userspace we a: get rid of CPU consumption of such broken guests b: keep the program old PSW. This allows to find out the original illegal operation - making debugging such early boot issues much easier than with single stepping Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-01-30KVM: s390: guestdbg: filter PER i-fetch on EXECUTE properlyDavid Hildenbrand
When we get a PER i-fetch event on an EXECUTE or EXECUTE RELATIVE LONG instruction, because the executed instruction generated a PER i-fetch event, then the PER address points at the EXECUTE function, not the fetched one. Therefore, when filtering PER events, we have to take care of the really fetched instruction, which we can only get by reading in guest virtual memory. For icpt code 4 and 56, we directly have additional information about an EXECUTE instruction at hand. For icpt code 8, we always have to read in guest virtual memory. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> [small fixes]
2016-10-20KVM: s390: reject invalid modes for runtime instrumentationChristian Borntraeger
Usually a validity intercept is a programming error of the host because of invalid entries in the state description. We can get a validity intercept if the mode of the runtime instrumentation control block is wrong. As the host does not know which modes are valid, this can be used by userspace to trigger a WARN. Instead of printing a WARN let's return an error to userspace as this can only happen if userspace provides a malformed initial value (e.g. on migration). The kernel should never warn on bogus input. Instead let's log it into the s390 debug feature. While at it, let's return -EINVAL for all validity intercepts as this will trigger an error in QEMU like error: kvm run failed Invalid argument PSW=mask 0404c00180000000 addr 000000000063c226 cc 00 R00=000000000000004f R01=0000000000000004 R02=0000000000760005 R03=000000007fe0a000 R04=000000000064ba2a R05=000000049db73dd0 R06=000000000082c4b0 R07=0000000000000041 R08=0000000000000002 R09=000003e0804042a8 R10=0000000496152c42 R11=000000007fe0afb0 [...] This will avoid an endless loop of validity intercepts. Cc: stable@vger.kernel.org # v4.5+ Fixes: c6e5f166373a ("KVM: s390: implement the RI support of guest") Acked-by: Fan Zhang <zhangfan@linux.vnet.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-09-08KVM: s390: lazy enable RIFan Zhang
Only enable runtime instrumentation if the guest issues an RI related instruction or if userspace changes the riccb to a valid state. This makes entry/exit a tiny bit faster. Initial patch by Christian Borntraeger Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: - ARM: GICv3 ITS emulation and various fixes. Removal of the old VGIC implementation. - s390: support for trapping software breakpoints, nested virtualization (vSIE), the STHYI opcode, initial extensions for CPU model support. - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups, preliminary to this and the upcoming support for hardware virtualization extensions. - x86: support for execute-only mappings in nested EPT; reduced vmexit latency for TSC deadline timer (by about 30%) on Intel hosts; support for more than 255 vCPUs. - PPC: bugfixes. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits) KVM: PPC: Introduce KVM_CAP_PPC_HTM MIPS: Select HAVE_KVM for MIPS64_R{2,6} MIPS: KVM: Reset CP0_PageMask during host TLB flush MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX() MIPS: KVM: Sign extend MFC0/RDHWR results MIPS: KVM: Fix 64-bit big endian dynamic translation MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase MIPS: KVM: Use 64-bit CP0_EBase when appropriate MIPS: KVM: Set CP0_Status.KX on MIPS64 MIPS: KVM: Make entry code MIPS64 friendly MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIPS: KVM: Use virt_to_phys() to get commpage PFN MIPS: Fix definition of KSEGX() for 64-bit KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD kvm: x86: nVMX: maintain internal copy of current VMCS KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures KVM: arm64: vgic-its: Simplify MAPI error handling KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers KVM: arm64: vgic-its: Turn device_id validation into generic ID validation ...
2016-07-18KVM: s390: allow user space to handle instr 0x0000David Hildenbrand
We will use illegal instruction 0x0000 for handling 2 byte sw breakpoints from user space. As it can be enabled dynamically via a capability, let's move setting of ICTL_OPEREXC to the post creation step, so we avoid any races when enabling that capability just while adding new cpus. Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-07-05KVM: s390: inject PER i-fetch events on applicable icptsDavid Hildenbrand
In case we have to emuluate an instruction or part of it (instruction, partial instruction, operation exception), we have to inject a PER instruction-fetching event for that instruction, if hardware told us to do so. In case we retry an instruction, we must not inject the PER event. Please note that we don't filter the events properly yet, so guest debugging will be visible for the guest. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Add sthyi emulationJanosch Frank
Store Hypervisor Information is an emulated z/VM instruction that provides a guest with basic information about the layers it is running on. This includes information about the cpu configuration of both the machine and the lpar, as well as their names, machine model and machine type. This information enables an application to determine the maximum capacity of CPs and IFLs available to software. The instruction is available whenever the facility bit 74 is set, otherwise executing it results in an operation exception. It is important to check the validity flags in the sections before using data from any structure member. It is not guaranteed that all members will be valid on all machines / machine configurations. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Add operation exception interception handlerJanosch Frank
This commit introduces code that handles operation exception interceptions. With this handler we can emulate instructions by using illegal opcodes. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10KVM: s390: Add stats for PEI eventsAlexander Yarygin
Add partial execution intercepted events in kvm_stats_debugfs. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-02-10KVM: s390: irq delivery should not rely on icptcodeDavid Hildenbrand
Program irq injection during program irq intercepts is the last candidates that injects nullifying irqs and relies on delivery to do the right thing. As we should not rely on the icptcode during any delivery (because that value will not be migrated), let's add a flag, telling prog IRQ delivery to not rewind the PSW in case of nullifying prog IRQs. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-02-10KVM: s390: clean up prog irq injection on prog irq icptsDavid Hildenbrand
__extract_prog_irq() is used only once for getting the program check data in one place. Let's combine it with an injection function to avoid a memset and to prevent misuse on injection by simplifying the interface to only have the VCPU as parameter. Reviewed-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>
2016-02-10KVM: s390: gaccess: introduce access modesDavid Hildenbrand
We will need special handling when fetching instructions, so let's introduce new guest access modes GACC_FETCH and GACC_STORE instead of a write flag. An additional patch will then introduce GACC_IFETCH. Reviewed-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>
2016-02-10KVM: s390: PSW forwarding / rewinding / ilc reworkDavid Hildenbrand
We have some confusion about ilc vs. ilen in our current code. So let's correctly use the term ilen when dealing with (ilc << 1). Program irq injection didn't take care of the correct ilc in case of irqs triggered by EXECUTE functions, let's provide one function kvm_s390_get_ilen() to take care of all that. Also, manually specifying in intercept handlers the size of the instruction (and sometimes overwriting that value for EXECUTE internally) doesn't make too much sense. So also provide the functions: - kvm_s390_retry_instr to retry the currently intercepted instruction - kvm_s390_rewind_psw to rewind the PSW without internal overwrites - kvm_s390_forward_psw to forward the PSW Reviewed-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>
2015-11-30KVM: s390: rewrite vcpu_post_run and drop out earlyDavid Hildenbrand
Let's rewrite this function to better reflect how we actually handle exit_code. By dropping out early we can save a few cycles. This especially speeds up sie exits caused by host irqs. Also, let's move the special -EOPNOTSUPP for intercepts to the place where it belongs and convert it to -EREMOTE. Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-10-29KVM: s390: use simple switch statement as multiplexerChristian Borntraeger
We currently do some magic shifting (by exploiting that exit codes are always a multiple of 4) and a table lookup to jump into the exit handlers. This causes some calculations and checks, just to do an potentially expensive function call. Changing that to a switch statement gives the compiler the chance to inline and dynamically decide between jump tables or inline compare and branches. In addition it makes the code more readable. bloat-o-meter gives me a small reduction in code size: add/remove: 0/7 grow/shrink: 1/1 up/down: 986/-1334 (-348) function old new delta kvm_handle_sie_intercept 72 1058 +986 handle_prog 704 696 -8 handle_noop 54 - -54 handle_partial_execution 60 - -60 intercept_funcs 120 - -120 handle_instruction 198 - -198 handle_validity 210 - -210 handle_stop 316 - -316 handle_external_interrupt 368 - -368 Right now my gcc does conditional branches instead of jump tables. The inlining seems to give us enough cycles as some micro-benchmarking shows minimal improvements, but still in noise. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2015-05-08KVM: s390: drop handling of interception code 12David Hildenbrand
Our implementation will never trigger interception code 12 as the responsible setting is never enabled - and never will be. The handler is dead code. Let's get rid of it. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17KVM: s390: Guest's memory access functions get access registersAlexander Yarygin
In access register mode, the write_guest() read_guest() and other functions will invoke the access register translation, which requires an ar, designated by one of the instruction fields. Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-06KVM: s390: Vector exceptionsEric Farman
A new exception type for vector instructions is introduced with the new processor, but is handled exactly like a Data Exception which is already handled by the system. Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: Take addressing mode into account for MVPG interceptionThomas Huth
The handler for MVPG partial execution interception does not take the current CPU addressing mode into account yet, so addresses are always treated as 64-bit addresses. For correct behaviour, we should properly handle 24-bit and 31-bit addresses, too. Since MVPG is defined to work with logical addresses, we can simply use guest_translate_address() to achieve the required behaviour (since DAT is disabled here, guest_translate_address() skips the MMU translation and only translates the address via kvm_s390_logical_to_effective() and kvm_s390_real_to_abs(), which is exactly what we want here). Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: only one external call may be pending at a timeDavid Hildenbrand
Only one external call may be pending at a vcpu at a time. For this reason, we have to detect whether the SIGP externcal call interpretation facility is available. If so, all external calls have to be injected using this mechanism. SIGP EXTERNAL CALL orders have to return whether another external call is already pending. This check was missing until now. SIGP SENSE hasn't returned yet in all conditions whether an external call was pending. If a SIGP EXTERNAL CALL irq is to be injected and one is already pending, -EBUSY is returned. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: a VCPU may only stop when no interrupts are left pendingDavid Hildenbrand
As a SIGP STOP is an interrupt with the least priority, it may only result in stop of the vcpu when no other interrupts are left pending. To detect whether a non-stop irq is pending, we need a way to mask out stop irqs from the general kvm_cpu_has_interrupt() function. For this reason, the existing function (with an outdated name) is replaced by kvm_s390_vcpu_has_irq() which allows to mask out pending stop irqs. Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: handle stop irqs without action_bitsDavid Hildenbrand
This patch removes the famous action_bits and moves the handling of SIGP STOP AND STORE STATUS directly into the SIGP STOP interrupt. The new local interrupt infrastructure is used to track pending stop requests. STOP irqs are the only irqs that don't get actively delivered. They remain pending until the stop function is executed (=stop intercept). If another STOP irq is already pending, -EBUSY will now be returned (needed for the SIGP handling code). Migration of pending SIGP STOP (AND STORE STATUS) orders should now be supported out of the box. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: handle pending local interrupts via bitmapJens Freimann
This patch adapts handling of local interrupts to be more compliant with the z/Architecture Principles of Operation and introduces a data structure which allows more efficient handling of interrupts. * get rid of li->active flag, use bitmap instead * Keep interrupts in a bitmap instead of a list * Deliver interrupts in the order of their priority as defined in the PoP * Use a second bitmap for sigp emergency requests, as a CPU can have one request pending from every other CPU in the system. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: Fix rewinding of the PSW pointing to an EXECUTE instructionThomas Huth
A couple of our interception handlers rewind the PSW to the beginning of the instruction to run the intercepted instruction again during the next SIE entry. This normally works fine, but there is also the possibility that the instruction did not get run directly but via an EXECUTE instruction. In this case, the PSW does not point to the instruction that caused the interception, but to the EXECUTE instruction! So we've got to rewind the PSW to the beginning of the EXECUTE instruction instead. This is now accomplished with a new helper function kvm_s390_rewind_psw(). Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>