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/uapi/xen/gntalloc.h | 87 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 include/uapi/xen/gntalloc.h (limited to 'include/uapi/xen/gntalloc.h') diff --git a/include/uapi/xen/gntalloc.h b/include/uapi/xen/gntalloc.h new file mode 100644 index 000000000..310928267 --- /dev/null +++ b/include/uapi/xen/gntalloc.h @@ -0,0 +1,87 @@ +/****************************************************************************** + * gntalloc.h + * + * Interface to /dev/xen/gntalloc. + * + * Author: Daniel De Graaf + * + * This file is in the public domain. + */ + +#ifndef __LINUX_PUBLIC_GNTALLOC_H__ +#define __LINUX_PUBLIC_GNTALLOC_H__ + +#include + +/* + * Allocates a new page and creates a new grant reference. + */ +#define IOCTL_GNTALLOC_ALLOC_GREF \ +_IOC(_IOC_NONE, 'G', 5, sizeof(struct ioctl_gntalloc_alloc_gref)) +struct ioctl_gntalloc_alloc_gref { + /* IN parameters */ + /* The ID of the domain to be given access to the grants. */ + __u16 domid; + /* Flags for this mapping */ + __u16 flags; + /* Number of pages to map */ + __u32 count; + /* OUT parameters */ + /* The offset to be used on a subsequent call to mmap(). */ + __u64 index; + /* The grant references of the newly created grant, one per page */ + /* Variable size, depending on count */ + union { + __u32 gref_ids[1]; + __DECLARE_FLEX_ARRAY(__u32, gref_ids_flex); + }; +}; + +#define GNTALLOC_FLAG_WRITABLE 1 + +/* + * Deallocates the grant reference, allowing the associated page to be freed if + * no other domains are using it. + */ +#define IOCTL_GNTALLOC_DEALLOC_GREF \ +_IOC(_IOC_NONE, 'G', 6, sizeof(struct ioctl_gntalloc_dealloc_gref)) +struct ioctl_gntalloc_dealloc_gref { + /* IN parameters */ + /* The offset returned in the map operation */ + __u64 index; + /* Number of references to unmap */ + __u32 count; +}; + +/* + * Sets up an unmap notification within the page, so that the other side can do + * cleanup if this side crashes. Required to implement cross-domain robust + * mutexes or close notification on communication channels. + * + * Each mapped page only supports one notification; multiple calls referring to + * the same page overwrite the previous notification. You must clear the + * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it + * to occur. + */ +#define IOCTL_GNTALLOC_SET_UNMAP_NOTIFY \ +_IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntalloc_unmap_notify)) +struct ioctl_gntalloc_unmap_notify { + /* IN parameters */ + /* Offset in the file descriptor for a byte within the page (same as + * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to + * be cleared. Otherwise, it can be any byte in the page whose + * notification we are adjusting. + */ + __u64 index; + /* Action(s) to take on unmap */ + __u32 action; + /* Event channel to notify */ + __u32 event_channel_port; +}; + +/* Clear (set to zero) the byte specified by index */ +#define UNMAP_NOTIFY_CLEAR_BYTE 0x1 +/* Send an interrupt on the indicated event channel */ +#define UNMAP_NOTIFY_SEND_EVENT 0x2 + +#endif /* __LINUX_PUBLIC_GNTALLOC_H__ */ -- cgit v1.3.1