kernel/git/stable/linux.git/arch/powerpc/kvm, branch linux-6.7.y

KVM: PPC: Book3S HV: Fix L2 guest reboot failure due to empty 'arch_compat'

2024-03-01T12:41:56+00:00

[ Upstream commit 20c8c4dafe93e82441583e93bd68c0d256d7bed4 ] Currently, rebooting a pseries nested qemu-kvm guest (L2) results in below error as L1 qemu sends PVR value 'arch_compat' == 0 via ppc_set_compat ioctl. This triggers a condition failure in kvmppc_set_arch_compat() resulting in an EINVAL. qemu-system-ppc64: Unable to set CPU compatibility mode in KVM: Invalid argument Also, a value of 0 for arch_compat generally refers the default compatibility of the host. But, arch_compat, being a Guest Wide Element in nested API v2, cannot be set to 0 in GSB as PowerVM (L0) expects a non-zero value. A value of 0 triggers a kernel trap during a reboot and consequently causes it to fail: [ 22.106360] reboot: Restarting system KVM: unknown exit, hardware reason ffffffffffffffea NIP 0000000000000100 LR 000000000000fe44 CTR 0000000000000000 XER 0000000020040092 CPU#0 MSR 0000000000001000 HID0 0000000000000000 HF 6c000000 iidx 3 didx 3 TB 00000000 00000000 DECR 0 GPR00 0000000000000000 0000000000000000 c000000002a8c300 000000007fe00000 GPR04 0000000000000000 0000000000000000 0000000000001002 8000000002803033 GPR08 000000000a000000 0000000000000000 0000000000000004 000000002fff0000 GPR12 0000000000000000 c000000002e10000 0000000105639200 0000000000000004 GPR16 0000000000000000 000000010563a090 0000000000000000 0000000000000000 GPR20 0000000105639e20 00000001056399c8 00007fffe54abab0 0000000105639288 GPR24 0000000000000000 0000000000000001 0000000000000001 0000000000000000 GPR28 0000000000000000 0000000000000000 c000000002b30840 0000000000000000 CR 00000000 [ - - - - - - - - ] RES 000@ffffffffffffffff SRR0 0000000000000000 SRR1 0000000000000000 PVR 0000000000800200 VRSAVE 0000000000000000 SPRG0 0000000000000000 SPRG1 0000000000000000 SPRG2 0000000000000000 SPRG3 0000000000000000 SPRG4 0000000000000000 SPRG5 0000000000000000 SPRG6 0000000000000000 SPRG7 0000000000000000 HSRR0 0000000000000000 HSRR1 0000000000000000 CFAR 0000000000000000 LPCR 0000000000020400 PTCR 0000000000000000 DAR 0000000000000000 DSISR 0000000000000000 kernel:trap=0xffffffea | pc=0x100 | msr=0x1000 This patch updates kvmppc_set_arch_compat() to use the host PVR value if 'compat_pvr' == 0 indicating that qemu doesn't want to enforce any specific PVR compat mode. The relevant part of the code might need a rework if PowerVM implements a support for `arch_compat == 0` in nestedv2 API. Fixes: 19d31c5f1157 ("KVM: PPC: Add support for nestedv2 guests") Reviewed-by: "Aneesh Kumar K.V (IBM)" Reviewed-by: Vaibhav Jain Signed-off-by: Amit Machhiwal Signed-off-by: Michael Ellerman Link: https://msgid.link/20240207054526.3720087-1-amachhiw@linux.ibm.com Signed-off-by: Sasha Levin

KVM: PPC: Book3S HV: Handle pending exceptions on guest entry with MSR_EE

2024-01-25T23:44:38+00:00

[ Upstream commit ecd10702baae5c16a91d139bde7eff84ce55daee ] Commit 026728dc5d41 ("KVM: PPC: Book3S HV P9: Inject pending xive interrupts at guest entry") changed guest entry so that if external interrupts are enabled, BOOK3S_IRQPRIO_EXTERNAL is not tested for. Test for this regardless of MSR_EE. For an L1 host, do not inject an interrupt, but always use LPCR_MER. If the L0 desires it can inject an interrupt. Fixes: 026728dc5d41 ("KVM: PPC: Book3S HV P9: Inject pending xive interrupts at guest entry") Signed-off-by: Nicholas Piggin [jpn: use kvmpcc_get_msr(), write commit message] Signed-off-by: Jordan Niethe Signed-off-by: Michael Ellerman Link: https://msgid.link/20231201132618.555031-7-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin

Merge tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2023-11-03T20:07:39+00:00

Pull powerpc updates from Michael Ellerman: - Add support for KVM running as a nested hypervisor under development versions of PowerVM, using the new PAPR nested virtualisation API - Add support for the BPF prog pack allocator - A rework of the non-server MMU handling to support execute-only on all platforms - Some optimisations & cleanups for the powerpc qspinlock code - Various other small features and fixes Thanks to Aboorva Devarajan, Aditya Gupta, Amit Machhiwal, Benjamin Gray, Christophe Leroy, Dr. David Alan Gilbert, Gaurav Batra, Gautam Menghani, Geert Uytterhoeven, Haren Myneni, Hari Bathini, Joel Stanley, Jordan Niethe, Julia Lawall, Kautuk Consul, Kuan-Wei Chiu, Michael Neuling, Minjie Du, Muhammad Muzammil, Naveen N Rao, Nicholas Piggin, Nick Child, Nysal Jan K.A, Peter Lafreniere, Rob Herring, Sachin Sant, Sebastian Andrzej Siewior, Shrikanth Hegde, Srikar Dronamraju, Stanislav Kinsburskii, Vaibhav Jain, Wang Yufen, Yang Yingliang, and Yuan Tan. * tag 'powerpc-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (100 commits) powerpc/vmcore: Add MMU information to vmcoreinfo Revert "powerpc: add `cur_cpu_spec` symbol to vmcoreinfo" powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free] powerpc/bpf: rename powerpc64_jit_data to powerpc_jit_data powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack powerpc/bpf: implement bpf_arch_text_copy powerpc/code-patching: introduce patch_instructions() powerpc/32s: Implement local_flush_tlb_page_psize() powerpc/pseries: use kfree_sensitive() in plpks_gen_password() powerpc/code-patching: Perform hwsync in __patch_instruction() in case of failure powerpc/fsl_msi: Use device_get_match_data() powerpc: Remove cpm_dp...() macros powerpc/qspinlock: Rename yield_propagate_owner tunable powerpc/qspinlock: Propagate sleepy if previous waiter is preempted powerpc/qspinlock: don't propagate the not-sleepy state powerpc/qspinlock: propagate owner preemptedness rather than CPU number powerpc/qspinlock: stop queued waiters trying to set lock sleepy powerpc/perf: Fix disabling BHRB and instruction sampling powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API powerpc/tools: Pass -mabi=elfv2 to gcc-check-mprofile-kernel.sh ...

Merge branch 'topic/ppc-kvm' into next

2023-10-27T09:58:03+00:00

Merge our KVM topic branch, this has been independently included in linux-next for most of the development cycle.

powerpc: Remove extern from function implementations

2023-10-19T06:12:47+00:00

Sparse reports several function implementations annotated with extern. This is clearly incorrect, likely just copied from an actual extern declaration in another file. Fix the sparse warnings by removing extern. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20231011053711.93427-6-bgray@linux.ibm.com

powerpc: Use NULL instead of 0 for null pointers

2023-10-19T06:12:47+00:00

Sparse reports several uses of 0 for pointer arguments and comparisons. Replace with NULL to better convey the intent. Remove entirely if a comparison to follow the kernel style of implicit boolean conversions. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20231011053711.93427-5-bgray@linux.ibm.com

docs: move powerpc under arch

2023-10-10T19:35:55+00:00

and fix all in-tree references. Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Signed-off-by: Costa Shulyupin Acked-by: Michael Ellerman Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20230826165737.2101199-1-costa.shul@redhat.com

KVM: PPC: Add support for nestedv2 guests

2023-09-14T12:04:24+00:00

A series of hcalls have been added to the PAPR which allow a regular guest partition to create and manage guest partitions of its own. KVM already had an interface that allowed this on powernv platforms. This existing interface will now be called "nestedv1". The newly added PAPR interface will be called "nestedv2". PHYP will support the nestedv2 interface. At this time the host side of the nestedv2 interface has not been implemented on powernv but there is no technical reason why it could not be added. The nestedv1 interface is still supported. Add support to KVM to utilize these hcalls to enable running nested guests as a pseries guest on PHYP. Overview of the new hcall usage: - L1 and L0 negotiate capabilities with H_GUEST_{G,S}ET_CAPABILITIES() - L1 requests the L0 create a L2 with H_GUEST_CREATE() and receives a handle to use in future hcalls - L1 requests the L0 create a L2 vCPU with H_GUEST_CREATE_VCPU() - L1 sets up the L2 using H_GUEST_SET and the H_GUEST_VCPU_RUN input buffer - L1 requests the L0 runs the L2 vCPU using H_GUEST_VCPU_RUN() - L2 returns to L1 with an exit reason and L1 reads the H_GUEST_VCPU_RUN output buffer populated by the L0 - L1 handles the exit using H_GET_STATE if necessary - L1 reruns L2 vCPU with H_GUEST_VCPU_RUN - L1 frees the L2 in the L0 with H_GUEST_DELETE() Support for the new API is determined by trying H_GUEST_GET_CAPABILITIES. On a successful return, use the nestedv2 interface. Use the vcpu register state setters for tracking modified guest state elements and copy the thread wide values into the H_GUEST_VCPU_RUN input buffer immediately before running a L2. The guest wide elements can not be added to the input buffer so send them with a separate H_GUEST_SET call if necessary. Make the vcpu register getter load the corresponding value from the real host with H_GUEST_GET. To avoid unnecessarily calling H_GUEST_GET, track which values have already been loaded between H_GUEST_VCPU_RUN calls. If an element is present in the H_GUEST_VCPU_RUN output buffer it also does not need to be loaded again. Tested-by: Sachin Sant Signed-off-by: Vaibhav Jain Signed-off-by: Gautam Menghani Signed-off-by: Kautuk Consul Signed-off-by: Amit Machhiwal Signed-off-by: Jordan Niethe Signed-off-by: Michael Ellerman Link: https://msgid.link/20230914030600.16993-11-jniethe5@gmail.com

KVM: PPC: Book3s HV: Hold LPIDs in an unsigned long

2023-09-14T12:04:24+00:00

The LPID register is 32 bits long. The host keeps the lpids for each guest in an unsigned word struct kvm_arch. Currently, LPIDs are already limited by mmu_lpid_bits and KVM_MAX_NESTED_GUESTS_SHIFT. The nestedv2 API returns a 64 bit "Guest ID" to be used be the L1 host for each L2 guest. This value is used as an lpid, e.g. it is the parameter used by H_RPT_INVALIDATE. To minimize needless special casing it makes sense to keep this "Guest ID" in struct kvm_arch::lpid. This means that struct kvm_arch::lpid is too small so prepare for this and make it an unsigned long. This is not a problem for the KVM-HV and nestedv1 cases as their lpid values are already limited to valid ranges so in those contexts the lpid can be used as an unsigned word safely as needed. In the PAPR, the H_RPT_INVALIDATE pid/lpid parameter is already specified as an unsigned long so change pseries_rpt_invalidate() to match that. Update the callers of pseries_rpt_invalidate() to also take an unsigned long if they take an lpid value. Signed-off-by: Jordan Niethe Signed-off-by: Michael Ellerman Link: https://msgid.link/20230914030600.16993-10-jniethe5@gmail.com

KVM: PPC: Add helper library for Guest State Buffers

2023-09-14T12:04:24+00:00

The PAPR "Nestedv2" guest API introduces the concept of a Guest State Buffer for communication about L2 guests between L1 and L0 hosts. In the new API, the L0 manages the L2 on behalf of the L1. This means that if the L1 needs to change L2 state (e.g. GPRs, SPRs, partition table...), it must request the L0 perform the modification. If the nested host needs to read L2 state likewise this request must go through the L0. The Guest State Buffer is a Type-Length-Value style data format defined in the PAPR which assigns all relevant partition state a unique identity. Unlike a typical TLV format the length is redundant as the length of each identity is fixed but is included for checking correctness. A guest state buffer consists of an element count followed by a stream of elements, where elements are composed of an ID number, data length, then the data: Header: <---4 bytes---> +----------------+----- | Element Count | Elements... +----------------+----- Element: <----2 bytes---> <-2 bytes-> <-Length bytes-> +----------------+-----------+----------------+ | Guest State ID | Length | Data | +----------------+-----------+----------------+ Guest State IDs have other attributes defined in the PAPR such as whether they are per thread or per guest, or read-only. Introduce a library for using guest state buffers. This includes support for actions such as creating buffers, adding elements to buffers, reading the value of elements and parsing buffers. This will be used later by the nestedv2 guest support. Signed-off-by: Jordan Niethe Signed-off-by: Michael Ellerman Link: https://msgid.link/20230914030600.16993-9-jniethe5@gmail.com