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/net/dsfield.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 include/net/dsfield.h (limited to 'include/net/dsfield.h') diff --git a/include/net/dsfield.h b/include/net/dsfield.h new file mode 100644 index 000000000..a59a57ffc --- /dev/null +++ b/include/net/dsfield.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* include/net/dsfield.h - Manipulation of the Differentiated Services field */ + +/* Written 1998-2000 by Werner Almesberger, EPFL ICA */ + + +#ifndef __NET_DSFIELD_H +#define __NET_DSFIELD_H + +#include +#include +#include +#include + + +static inline __u8 ipv4_get_dsfield(const struct iphdr *iph) +{ + return iph->tos; +} + + +static inline __u8 ipv6_get_dsfield(const struct ipv6hdr *ipv6h) +{ + return ntohs(*(__force const __be16 *)ipv6h) >> 4; +} + + +static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask, + __u8 value) +{ + __u32 check = ntohs((__force __be16)iph->check); + __u8 dsfield; + + dsfield = (iph->tos & mask) | value; + check += iph->tos; + if ((check+1) >> 16) check = (check+1) & 0xffff; + check -= dsfield; + check += check >> 16; /* adjust carry */ + iph->check = (__force __sum16)htons(check); + iph->tos = dsfield; +} + + +static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask, + __u8 value) +{ + __be16 *p = (__force __be16 *)ipv6h; + + *p = (*p & htons((((u16)mask << 4) | 0xf00f))) | htons((u16)value << 4); +} + + +#endif -- cgit v1.3.1