This change introduces support for confidential guests (SEV-ES, SEV-SNP and TDX) to reset/reboot just like other non-confidential guests. Currently, a reboot intiated from the confidential guest results in termination of the QEMU hypervisor as the CPUs are not resettable. As the initial state of the guest including private memory is locked and encrypted, the contents of that memory will not be accessible post reset. Hence a new KVM file descriptor must be opened to create a new confidential VM context closing the old one. All KVM VM specific ioctls must be called again. New VCPU file descriptors must be created against the new KVM fd and most VCPU ioctls must be called again as well.
This change perfoms closing of the old KVM fd and creating a new one. After the new KVM fd is opened, all generic and architecture specific ioctl calls are issued again. Notifiers are added to notify subsystems that: - The KVM file fd is about to be changed to state sync-ing from KVM to QEMU should be done if required. - The KVM file fd has changed, so ioctl calls to the new KVM fd has to be performed again. - That new VCPU fds are created so that VCPU ioctl calls must be called again where required. Specific subsystems use these notifiers to re-issue ioctl calls where required. Changes are made to SEV and TDX modules to reinitialize the confidential guest state and seal it again. Along the way, some bug fixes are made so that some initialization functions can be called again. Some refactoring of existing code is done so that both init and reset paths can use them. Tested on TDX and SEV-SNP. CI pipeline passes: https://gitlab.com/anisinha/qemu/-/pipelines/2211550528 Rebased on top of version 10.2.0-rc3 CC: [email protected] CC: [email protected] CC: [email protected] Ani Sinha (28): i386/kvm: avoid installing duplicate msr entries in msr_handlers hw/accel: add a per-accelerator callback to change VM accelerator handle system/physmem: add helper to reattach existing memory after KVM VM fd change accel/kvm: add changes required to support KVM VM file descriptor change accel/kvm: mark guest state as unprotected after vm file descriptor change accel/kvm: add a notifier to indicate KVM VM file descriptor has changed kvm/i386: implement architecture support for kvm file descriptor change hw/i386: refactor x86_bios_rom_init for reuse in confidential guest reset kvm/i386: reload firmware for confidential guest reset accel/kvm: Add notifier to inform that the KVM VM file fd is about to be changed accel/kvm: rebind current VCPUs to the new KVM VM file descriptor upon reset i386/tdx: refactor TDX firmware memory initialization code into a new function i386/tdx: finalize TDX guest state upon reset i386/tdx: add a pre-vmfd change notifier to reset tdx state i386/sev: add migration blockers only once i386/sev: add notifiers only once i386/sev: free existing launch update data and kernel hashes data on init i386/sev: add support for confidential guest reset hw/vfio: generate new file fd for pseudo device and rebind existing descriptors kvm/i8254: add support for confidential guest reset hw/hyperv/vmbus: add support for confidential guest reset accel/kvm: add a per-confidential class callback to unlock guest state kvm/xen-emu: re-initialize capabilities during confidential guest reset kvm/xen_evtchn: add support for confidential guest reset ppc/openpic: create a new openpic device and reattach mem region on coco reset kvm/vcpu: add notifiers to inform vcpu file descriptor change kvm/i386/apic: set local apic after vcpu file descriptors changed kvm/clock: add support for confidential guest reset accel/kvm/kvm-all.c | 354 +++++++++++++++++--- accel/stubs/kvm-stub.c | 26 ++ hw/hyperv/vmbus.c | 30 ++ hw/i386/kvm/apic.c | 13 + hw/i386/kvm/clock.c | 56 ++++ hw/i386/kvm/i8254.c | 84 +++-- hw/i386/kvm/xen_evtchn.c | 100 +++++- hw/i386/x86-common.c | 50 ++- hw/intc/openpic_kvm.c | 108 ++++-- hw/vfio/helpers.c | 81 ++++- include/accel/accel-ops.h | 1 + include/hw/i386/apic_internal.h | 1 + include/hw/i386/x86.h | 5 +- include/system/confidential-guest-support.h | 27 ++ include/system/kvm.h | 54 +++ include/system/physmem.h | 1 + system/physmem.c | 28 ++ system/runstate.c | 31 +- target/arm/kvm.c | 5 + target/i386/kvm/kvm.c | 189 +++++++++-- target/i386/kvm/tdx.c | 145 ++++++-- target/i386/kvm/tdx.h | 1 + target/i386/kvm/xen-emu.c | 45 ++- target/i386/sev.c | 110 +++++- target/loongarch/kvm/kvm.c | 5 + target/mips/kvm.c | 5 + target/ppc/kvm.c | 5 + target/riscv/kvm/kvm-cpu.c | 5 + target/s390x/kvm/kvm.c | 5 + 29 files changed, 1382 insertions(+), 188 deletions(-) -- 2.42.0
