arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__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 <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 60 insertions, 0 deletions

diff --git a/include/net/seg6_hmac.h b/include/net/seg6_hmac.h
new file mode 100644
index 000000000..e9f417259
--- /dev/null
+++ b/include/net/seg6_hmac.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ */
+
+#ifndef _NET_SEG6_HMAC_H
+#define _NET_SEG6_HMAC_H
+
+#include <crypto/sha1.h>
+#include <crypto/sha2.h>
+#include <net/flow.h>
+#include <net/ip6_fib.h>
+#include <net/sock.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/route.h>
+#include <net/seg6.h>
+#include <linux/seg6_hmac.h>
+#include <linux/rhashtable-types.h>
+
+#define SEG6_HMAC_RING_SIZE		256
+
+struct seg6_hmac_info {
+	struct rhash_head node;
+	struct rcu_head rcu;
+
+	u32 hmackeyid;
+	/* The raw key, kept only so it can be returned back to userspace */
+	char secret[SEG6_HMAC_SECRET_LEN];
+	u8 slen;
+	u8 alg_id;
+	/* The prepared key, which the calculations actually use */
+	union {
+		struct hmac_sha1_key sha1;
+		struct hmac_sha256_key sha256;
+	} key;
+};
+
+extern int seg6_hmac_compute(struct seg6_hmac_info *hinfo,
+			     struct ipv6_sr_hdr *hdr, struct in6_addr *saddr,
+			     u8 *output);
+extern struct seg6_hmac_info *seg6_hmac_info_lookup(struct net *net, u32 key);
+extern int seg6_hmac_info_add(struct net *net, u32 key,
+			      struct seg6_hmac_info *hinfo);
+extern int seg6_hmac_info_del(struct net *net, u32 key);
+extern int seg6_push_hmac(struct net *net, struct in6_addr *saddr,
+			  struct ipv6_sr_hdr *srh);
+extern bool seg6_hmac_validate_skb(struct sk_buff *skb);
+#ifdef CONFIG_IPV6_SEG6_HMAC
+extern int seg6_hmac_net_init(struct net *net);
+extern void seg6_hmac_net_exit(struct net *net);
+#else
+static inline int seg6_hmac_net_init(struct net *net) { return 0; }
+static inline void seg6_hmac_net_exit(struct net *net) {}
+#endif
+
+#endif