From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- include/kvm/iodev.h | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 include/kvm/iodev.h (limited to 'include/kvm/iodev.h') diff --git a/include/kvm/iodev.h b/include/kvm/iodev.h new file mode 100644 index 000000000..56619e332 --- /dev/null +++ b/include/kvm/iodev.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __KVM_IODEV_H__ +#define __KVM_IODEV_H__ + +#include +#include + +struct kvm_io_device; +struct kvm_vcpu; + +/** + * kvm_io_device_ops are called under kvm slots_lock. + * read and write handlers return 0 if the transaction has been handled, + * or non-zero to have it passed to the next device. + **/ +struct kvm_io_device_ops { + int (*read)(struct kvm_vcpu *vcpu, + struct kvm_io_device *this, + gpa_t addr, + int len, + void *val); + int (*write)(struct kvm_vcpu *vcpu, + struct kvm_io_device *this, + gpa_t addr, + int len, + const void *val); + void (*destructor)(struct kvm_io_device *this); +}; + + +struct kvm_io_device { + const struct kvm_io_device_ops *ops; +}; + +static inline void kvm_iodevice_init(struct kvm_io_device *dev, + const struct kvm_io_device_ops *ops) +{ + dev->ops = ops; +} + +static inline int kvm_iodevice_read(struct kvm_vcpu *vcpu, + struct kvm_io_device *dev, gpa_t addr, + int l, void *v) +{ + return dev->ops->read ? dev->ops->read(vcpu, dev, addr, l, v) + : -EOPNOTSUPP; +} + +static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu, + struct kvm_io_device *dev, gpa_t addr, + int l, const void *v) +{ + return dev->ops->write ? dev->ops->write(vcpu, dev, addr, l, v) + : -EOPNOTSUPP; +} + +#endif /* __KVM_IODEV_H__ */ -- cgit v1.3.1