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qemu/target/i386/kvm/xen-emu.h

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i386/kvm: Add xen-version KVM accelerator property and init KVM Xen support This just initializes the basic Xen support in KVM for now. Only permitted on TYPE_PC_MACHINE because that's where the sysbus devices for Xen heap overlay, event channel, grant tables and other stuff will exist. There's no point having the basic hypercall support if nothing else works. Provide sysemu/kvm_xen.h and a kvm_xen_get_caps() which will be used later by support devices. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2022-12-03 20:51:13 +03:00
/*
* Xen HVM emulation support in KVM
*
* Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
* Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef QEMU_I386_KVM_XEN_EMU_H
#define QEMU_I386_KVM_XEN_EMU_H
i386/kvm: handle Xen HVM cpuid leaves 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>
2022-12-06 13:48:53 +03:00
#define XEN_HYPERCALL_MSR 0x40000000
#define XEN_HYPERCALL_MSR_HYPERV 0x40000200
i386/kvm: Add xen-version KVM accelerator property and init KVM Xen support This just initializes the basic Xen support in KVM for now. Only permitted on TYPE_PC_MACHINE because that's where the sysbus devices for Xen heap overlay, event channel, grant tables and other stuff will exist. There's no point having the basic hypercall support if nothing else works. Provide sysemu/kvm_xen.h and a kvm_xen_get_caps() which will be used later by support devices. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2022-12-03 20:51:13 +03:00
i386/kvm: handle Xen HVM cpuid leaves 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>
2022-12-06 13:48:53 +03:00
#define XEN_CPUID_SIGNATURE 0
#define XEN_CPUID_VENDOR 1
#define XEN_CPUID_HVM_MSR 2
#define XEN_CPUID_TIME 3
#define XEN_CPUID_HVM 4
#define XEN_VERSION(maj, min) ((maj) << 16 | (min))
int kvm_xen_init(KVMState *s, uint32_t hypercall_msr);
i386/kvm: Set Xen vCPU ID in KVM 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>
2022-12-16 14:05:29 +03:00
int kvm_xen_init_vcpu(CPUState *cs);
i386/xen: handle guest hypercalls 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>
2018-06-13 17:14:31 +03:00
int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit);
i386/xen: handle VCPUOP_register_vcpu_info 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>
2018-06-29 17:54:50 +03:00
int kvm_put_xen_state(CPUState *cs);
int kvm_get_xen_state(CPUState *cs);
hw/xen: Support HVM_PARAM_CALLBACK_TYPE_GSI callback 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>
2022-12-15 23:35:24 +03:00
void kvm_xen_maybe_deassert_callback(CPUState *cs);
i386/kvm: Add xen-version KVM accelerator property and init KVM Xen support This just initializes the basic Xen support in KVM for now. Only permitted on TYPE_PC_MACHINE because that's where the sysbus devices for Xen heap overlay, event channel, grant tables and other stuff will exist. There's no point having the basic hypercall support if nothing else works. Provide sysemu/kvm_xen.h and a kvm_xen_get_caps() which will be used later by support devices. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2022-12-03 20:51:13 +03:00
#endif /* QEMU_I386_KVM_XEN_EMU_H */
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