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2023-08-24kvm: Introduce kvm_arch_get_default_type hookAkihiko Odaki
kvm_arch_get_default_type() returns the default KVM type. This hook is particularly useful to derive a KVM type that is valid for "none" machine model, which is used by libvirt to probe the availability of KVM. For MIPS, the existing mips_kvm_type() is reused. This function ensures the availability of VZ which is mandatory to use KVM on the current QEMU. Cc: qemu-stable@nongnu.org Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Message-id: 20230727073134.134102-2-akihiko.odaki@daynix.com Reviewed-by: Peter Maydell <peter.maydell@linaro.org> [PMM: added doc comment for new function] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> (cherry picked from commit 5e0d65909c6f335d578b90491e165440c99adf81) Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2023-08-01i386/xen: consistent locking around Xen singleshot timersDavid Woodhouse
Coverity points out (CID 1507534, 1507968) that we sometimes access env->xen_singleshot_timer_ns under the protection of env->xen_timers_lock and sometimes not. This isn't always an issue. There are two modes for the timers; if the kernel supports the EVTCHN_SEND capability then it handles all the timer hypercalls and delivery internally, and all we use the field for is to get/set the timer as part of the vCPU state via an ioctl(). If the kernel doesn't have that support, then we do all the emulation within qemu, and *those* are the code paths where we actually care about the locking. But it doesn't hurt to be a little bit more consistent and avoid having to explain *why* it's OK. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org> Message-Id: <20230801175747.145906-3-dwmw2@infradead.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-07-07target/i386: Allow MCDT_NO if host supportsTao Su
MCDT_NO bit indicates HW contains the security fix and doesn't need to be mitigated to avoid data-dependent behaviour for certain instructions. It needs no hypervisor support. Treat it as supported regardless of what KVM reports. Signed-off-by: Tao Su <tao1.su@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-ID: <20230706054949.66556-4-tao1.su@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-06-20meson: Replace softmmu_ss -> system_ssPhilippe Mathieu-Daudé
We use the user_ss[] array to hold the user emulation sources, and the softmmu_ss[] array to hold the system emulation ones. Hold the latter in the 'system_ss[]' array for parity with user emulation. Mechanical change doing: $ sed -i -e s/softmmu_ss/system_ss/g $(git grep -l softmmu_ss) Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20230613133347.82210-10-philmd@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-03-22*: Add missing includes of qemu/error-report.hRichard Henderson
This had been pulled in via qemu/plugin.h from hw/core/cpu.h, but that will be removed. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-Id: <20230310195252.210956-5-richard.henderson@linaro.org> [AJB: add various additional cases shown by CI] Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230315174331.2959-15-alex.bennee@linaro.org> Reviewed-by: Emilio Cota <cota@braap.org>
2023-03-15Fix build without CONFIG_XEN_EMUMiroslav Rezanina
Upstream commit ddf0fd9ae1 "hw/xen: Support HVM_PARAM_CALLBACK_TYPE_GSI callback" added kvm_xen_maybe_deassert_callback usage to target/i386/kvm/kvm.c file without conditional preprocessing check. This breaks any build not using CONFIG_XEN_EMU. Protect call by conditional preprocessing to allow build without CONFIG_XEN_EMU. Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20230308130557.2420-1-mrezanin@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-03-07hw/xen: Implement soft reset for emulated gnttabDavid Woodhouse
This is only part of it; we will also need to get the PV back end drivers to tear down their own mappings (or do it for them, but they kind of need to stop using the pointers too). Some more work on the actual PV back ends and xen-bus code is going to be needed to really make soft reset and migration fully functional, and this part is the basis for that. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01kvm/i386: Add xen-evtchn-max-pirq propertyDavid Woodhouse
The default number of PIRQs is set to 256 to avoid issues with 32-bit MSI devices. Allow it to be increased if the user desires. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Support MSI mapping to PIRQDavid Woodhouse
The way that Xen handles MSI PIRQs is kind of awful. There is a special MSI message which targets a PIRQ. The vector in the low bits of data must be zero. The low 8 bits of the PIRQ# are in the destination ID field, the extended destination ID field is unused, and instead the high bits of the PIRQ# are in the high 32 bits of the address. Using the high bits of the address means that we can't intercept and translate these messages in kvm_send_msi(), because they won't be caught by the APIC — addresses like 0x1000fee46000 aren't in the APIC's range. So we catch them in pci_msi_trigger() instead, and deliver the event channel directly. That isn't even the worst part. The worst part is that Xen snoops on writes to devices' MSI vectors while they are *masked*. When a MSI message is written which looks like it targets a PIRQ, it remembers the device and vector for later. When the guest makes a hypercall to bind that PIRQ# (snooped from a marked MSI vector) to an event channel port, Xen *unmasks* that MSI vector on the device. Xen guests using PIRQ delivery of MSI don't ever actually unmask the MSI for themselves. Now that this is working we can finally enable XENFEAT_hvm_pirqs and let the guest use it all. Tested with passthrough igb and emulated e1000e + AHCI. CPU0 CPU1 0: 65 0 IO-APIC 2-edge timer 1: 0 14 xen-pirq 1-ioapic-edge i8042 4: 0 846 xen-pirq 4-ioapic-edge ttyS0 8: 1 0 xen-pirq 8-ioapic-edge rtc0 9: 0 0 xen-pirq 9-ioapic-level acpi 12: 257 0 xen-pirq 12-ioapic-edge i8042 24: 9600 0 xen-percpu -virq timer0 25: 2758 0 xen-percpu -ipi resched0 26: 0 0 xen-percpu -ipi callfunc0 27: 0 0 xen-percpu -virq debug0 28: 1526 0 xen-percpu -ipi callfuncsingle0 29: 0 0 xen-percpu -ipi spinlock0 30: 0 8608 xen-percpu -virq timer1 31: 0 874 xen-percpu -ipi resched1 32: 0 0 xen-percpu -ipi callfunc1 33: 0 0 xen-percpu -virq debug1 34: 0 1617 xen-percpu -ipi callfuncsingle1 35: 0 0 xen-percpu -ipi spinlock1 36: 8 0 xen-dyn -event xenbus 37: 0 6046 xen-pirq -msi ahci[0000:00:03.0] 38: 1 0 xen-pirq -msi-x ens4 39: 0 73 xen-pirq -msi-x ens4-rx-0 40: 14 0 xen-pirq -msi-x ens4-rx-1 41: 0 32 xen-pirq -msi-x ens4-tx-0 42: 47 0 xen-pirq -msi-x ens4-tx-1 Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement emulated PIRQ hypercall supportDavid Woodhouse
This wires up the basic infrastructure but the actual interrupts aren't there yet, so don't advertise it to the guest. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: Implement HYPERVISOR_physdev_opDavid Woodhouse
Just hook up the basic hypercalls to stubs in xen_evtchn.c for now. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Add xen_xenstore device for xenstore emulationDavid Woodhouse
Just the basic shell, with the event channel hookup. It only dumps the buffer for now; a real ring implmentation will come in a subsequent patch. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: handle HVMOP_get_paramJoao Martins
Which is used to fetch xenstore PFN and port to be used by the guest. This is preallocated by the toolstack when guest will just read those and use it straight away. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: Reserve Xen special pages for console, xenstore ringsDavid Woodhouse
Xen has eight frames at 0xfeff8000 for this; we only really need two for now and KVM puts the identity map at 0xfeffc000, so limit ourselves to four. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: handle PV timer hypercallsJoao Martins
Introduce support for one shot and periodic mode of Xen PV timers, whereby timer interrupts come through a special virq event channel with deadlines being set through: 1) set_timer_op hypercall (only oneshot) 2) vcpu_op hypercall for {set,stop}_{singleshot,periodic}_timer hypercalls Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement GNTTABOP_query_sizeDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: Implement HYPERVISOR_grant_table_op and GNTTABOP_[gs]et_versonDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Add xen_gnttab device for grant table emulationDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01kvm/i386: Add xen-gnttab-max-frames propertyDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Support HVM_PARAM_CALLBACK_TYPE_PCI_INTX callbackDavid Woodhouse
The guest is permitted to specify an arbitrary domain/bus/device/function and INTX pin from which the callback IRQ shall appear to have come. In QEMU we can only easily do this for devices that actually exist, and even that requires us "knowing" that it's a PCMachine in order to find the PCI root bus — although that's OK really because it's always true. We also don't get to get notified of INTX routing changes, because we can't do that as a passive observer; if we try to register a notifier it will overwrite any existing notifier callback on the device. But in practice, guests using PCI_INTX will only ever use pin A on the Xen platform device, and won't swizzle the INTX routing after they set it up. So this is just fine. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Support HVM_PARAM_CALLBACK_TYPE_GSI callbackDavid Woodhouse
The GSI callback (and later PCI_INTX) is a level triggered interrupt. It is asserted when an event channel is delivered to vCPU0, and is supposed to be cleared when the vcpu_info->evtchn_upcall_pending field for vCPU0 is cleared again. Thankfully, Xen does *not* assert the GSI if the guest sets its own evtchn_upcall_pending field; we only need to assert the GSI when we have delivered an event for ourselves. So that's the easy part, kind of. There's a slight complexity in that we need to hold the BQL before we can call qemu_set_irq(), and we definitely can't do that while holding our own port_lock (because we'll need to take that from the qemu-side functions that the PV backend drivers will call). So if we end up wanting to set the IRQ in a context where we *don't* already hold the BQL, defer to a BH. However, we *do* need to poll for the evtchn_upcall_pending flag being cleared. In an ideal world we would poll that when the EOI happens on the PIC/IOAPIC. That's how it works in the kernel with the VFIO eventfd pairs — one is used to trigger the interrupt, and the other works in the other direction to 'resample' on EOI, and trigger the first eventfd again if the line is still active. However, QEMU doesn't seem to do that. Even VFIO level interrupts seem to be supported by temporarily unmapping the device's BARs from the guest when an interrupt happens, then trapping *all* MMIO to the device and sending the 'resample' event on *every* MMIO access until the IRQ is cleared! Maybe in future we'll plumb the 'resample' concept through QEMU's irq framework but for now we'll do what Xen itself does: just check the flag on every vmexit if the upcall GSI is known to be asserted. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_resetDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_bind_vcpuDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_bind_interdomainDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_alloc_unboundDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_sendDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_bind_ipiDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_bind_virqDavid Woodhouse
Add the array of virq ports to each vCPU so that we can deliver timers, debug ports, etc. Global virqs are allocated against vCPU 0 initially, but can be migrated to other vCPUs (when we implement that). The kernel needs to know about VIRQ_TIMER in order to accelerate timers, so tell it via KVM_XEN_VCPU_ATTR_TYPE_TIMER. Also save/restore the value of the singleshot timer across migration, as the kernel will handle the hypercalls automatically now. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_unmaskDavid Woodhouse
This finally comes with a mechanism for actually injecting events into the guest vCPU, with all the atomic-test-and-set that's involved in setting the bit in the shinfo, then the index in the vcpu_info, and injecting either the lapic vector as MSI, or letting KVM inject the bare vector. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_closeDavid Woodhouse
It calls an internal close_port() helper which will also be used from EVTCHNOP_reset and will actually do the work to disconnect/unbind a port once any of that is actually implemented in the first place. That in turn calls a free_port() internal function which will be in error paths after allocation. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Implement EVTCHNOP_statusDavid Woodhouse
This adds the basic structure for maintaining the port table and reporting the status of ports therein. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: Add support for Xen event channel delivery to vCPUDavid Woodhouse
The kvm_xen_inject_vcpu_callback_vector() function will either deliver the per-vCPU local APIC vector (as an MSI), or just kick the vCPU out of the kernel to trigger KVM's automatic delivery of the global vector. Support for asserting the GSI/PCI_INTX callbacks will come later. Also add kvm_xen_get_vcpu_info_hva() which returns the vcpu_info of a given vCPU. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01hw/xen: Add xen_evtchn device for event channel emulationDavid Woodhouse
Include basic support for setting HVM_PARAM_CALLBACK_IRQ to the global vector method HVM_PARAM_CALLBACK_TYPE_VECTOR, which is handled in-kernel by raising the vector whenever the vCPU's vcpu_info->evtchn_upcall_pending flag is set. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HVMOP_set_paramAnkur Arora
This is the hook for adding the HVM_PARAM_CALLBACK_IRQ parameter in a subsequent commit. Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Split out from another commit] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HVMOP_set_evtchn_upcall_vectorAnkur Arora
The HVMOP_set_evtchn_upcall_vector hypercall sets the per-vCPU upcall vector, to be delivered to the local APIC just like an MSI (with an EOI). This takes precedence over the system-wide delivery method set by the HVMOP_set_param hypercall with HVM_PARAM_CALLBACK_IRQ. It's used by Windows and Xen (PV shim) guests but normally not by Linux. Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Rework for upstream kernel changes and split from HVMOP_set_param] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HYPERVISOR_event_channel_opJoao Martins
Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Ditch event_channel_op_compat which was never available to HVM guests] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: handle VCPUOP_register_runstate_memory_areaJoao Martins
Allow guest to setup the vcpu runstates which is used as steal clock. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: handle VCPUOP_register_vcpu_time_infoJoao Martins
In order to support Linux vdso in Xen. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: handle VCPUOP_register_vcpu_infoJoao Martins
Handle the hypercall to set a per vcpu info, and also wire up the default vcpu_info in the shared_info page for the first 32 vCPUs. To avoid deadlock within KVM a vCPU thread must set its *own* vcpu_info rather than it being set from the context in which the hypercall is invoked. Add the vcpu_info (and default) GPA to the vmstate_x86_cpu for migration, and restore it in kvm_arch_put_registers() appropriately. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HYPERVISOR_vcpu_opJoao Martins
This is simply when guest tries to register a vcpu_info and since vcpu_info placement is optional in the minimum ABI therefore we can just fail with -ENOSYS Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HYPERVISOR_hvm_opJoao Martins
This is when guest queries for support for HVMOP_pagetable_dying. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement XENMEM_add_to_physmap_batchDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HYPERVISOR_memory_opJoao Martins
Specifically XENMEM_add_to_physmap with space XENMAPSPACE_shared_info to allow the guest to set its shared_info page. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Use the xen_overlay device, add compat support] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: manage and save/restore Xen guest long_mode settingDavid Woodhouse
Xen will "latch" the guest's 32-bit or 64-bit ("long mode") setting when the guest writes the MSR to fill in the hypercall page, or when the guest sets the event channel callback in HVM_PARAM_CALLBACK_IRQ. KVM handles the former and sets the kernel's long_mode flag accordingly. The latter will be handled in userspace. Keep them in sync by noticing when a hypercall is made in a mode that doesn't match qemu's idea of the guest mode, and resyncing from the kernel. Do that same sync right before serialization too, in case the guest has set the hypercall page but hasn't yet made a system call. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: Implement SCHEDOP_poll and SCHEDOP_yieldDavid Woodhouse
They both do the same thing and just call sched_yield. This is enough to stop the Linux guest panicking when running on a host kernel which doesn't intercept SCHEDOP_poll and lets it reach userspace. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HYPERVISOR_sched_op, SCHEDOP_shutdownJoao Martins
It allows to shutdown itself via hypercall with any of the 3 reasons: 1) self-reboot 2) shutdown 3) crash Implementing SCHEDOP_shutdown sub op let us handle crashes gracefully rather than leading to triple faults if it remains unimplemented. In addition, the SHUTDOWN_soft_reset reason is used for kexec, to reset Xen shared pages and other enlightenments and leave a clean slate for the new kernel without the hypervisor helpfully writing information at unexpected addresses. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Ditch sched_op_compat which was never available for HVM guests, Add SCHEDOP_soft_reset] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: implement HYPERVISOR_xen_versionJoao Martins
This is just meant to serve as an example on how we can implement hypercalls. xen_version specifically since Qemu does all kind of feature controllability. So handling that here seems appropriate. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Implement kvm_gva_rw() safely] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/xen: handle guest hypercallsJoao Martins
This means handling the new exit reason for Xen but still crashing on purpose. As we implement each of the hypercalls we will then return the right return code. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Add CPL to hypercall tracing, disallow hypercalls from CPL > 0] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/kvm: Set Xen vCPU ID in KVMDavid Woodhouse
There are (at least) three different vCPU ID number spaces. One is the internal KVM vCPU index, based purely on which vCPU was chronologically created in the kernel first. If userspace threads are all spawned and create their KVM vCPUs in essentially random order, then the KVM indices are basically random too. The second number space is the APIC ID space, which is consistent and useful for referencing vCPUs. MSIs will specify the target vCPU using the APIC ID, for example, and the KVM Xen APIs also take an APIC ID from userspace whenever a vCPU needs to be specified (as opposed to just using the appropriate vCPU fd). The third number space is not normally relevant to the kernel, and is the ACPI/MADT/Xen CPU number which corresponds to cs->cpu_index. But Xen timer hypercalls use it, and Xen timer hypercalls *really* want to be accelerated in the kernel rather than handled in userspace, so the kernel needs to be told. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01i386/kvm: handle Xen HVM cpuid leavesJoao Martins
Introduce support for emulating CPUID for Xen HVM guests. It doesn't make sense to advertise the KVM leaves to a Xen guest, so do Xen unconditionally when the xen-version machine property is set. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> [dwmw2: Obtain xen_version from KVM property, make it automatic] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>