From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
James Morse <james.morse@arm.com>,
Christoffer Dall <cdall@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <marc.zyngier@arm.com>
Subject: [PATCH 4.9 47/66] arm64: alternatives: use tpidr_el2 on VHE hosts
Date: Fri, 20 Jul 2018 14:14:04 +0200 [thread overview]
Message-ID: <20180720121409.948580976@linuxfoundation.org> (raw)
In-Reply-To: <20180720121407.228772286@linuxfoundation.org>
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: James Morse <james.morse@arm.com>
Commit 6d99b68933fbcf51f84fcbba49246ce1209ec193 upstream.
Now that KVM uses tpidr_el2 in the same way as Linux's cpu_offset in
tpidr_el1, merge the two. This saves KVM from save/restoring tpidr_el1
on VHE hosts, and allows future code to blindly access per-cpu variables
without triggering world-switch.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/include/asm/alternative.h | 2 ++
arch/arm64/include/asm/assembler.h | 8 ++++++++
arch/arm64/include/asm/percpu.h | 12 ++++++++++--
arch/arm64/kernel/alternative.c | 9 +++++----
arch/arm64/kernel/cpufeature.c | 17 +++++++++++++++++
5 files changed, 42 insertions(+), 6 deletions(-)
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -11,6 +11,8 @@
#include <linux/stddef.h>
#include <linux/stringify.h>
+extern int alternatives_applied;
+
struct alt_instr {
s32 orig_offset; /* offset to original instruction */
s32 alt_offset; /* offset to replacement instruction */
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -245,7 +245,11 @@ lr .req x30 // link register
*/
.macro adr_this_cpu, dst, sym, tmp
adr_l \dst, \sym
+alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
mrs \tmp, tpidr_el1
+alternative_else
+ mrs \tmp, tpidr_el2
+alternative_endif
add \dst, \dst, \tmp
.endm
@@ -256,7 +260,11 @@ lr .req x30 // link register
*/
.macro ldr_this_cpu dst, sym, tmp
adr_l \dst, \sym
+alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
mrs \tmp, tpidr_el1
+alternative_else
+ mrs \tmp, tpidr_el2
+alternative_endif
ldr \dst, [\dst, \tmp]
.endm
--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -16,9 +16,14 @@
#ifndef __ASM_PERCPU_H
#define __ASM_PERCPU_H
+#include <asm/alternative.h>
+
static inline void set_my_cpu_offset(unsigned long off)
{
- asm volatile("msr tpidr_el1, %0" :: "r" (off) : "memory");
+ asm volatile(ALTERNATIVE("msr tpidr_el1, %0",
+ "msr tpidr_el2, %0",
+ ARM64_HAS_VIRT_HOST_EXTN)
+ :: "r" (off) : "memory");
}
static inline unsigned long __my_cpu_offset(void)
@@ -29,7 +34,10 @@ static inline unsigned long __my_cpu_off
* We want to allow caching the value, so avoid using volatile and
* instead use a fake stack read to hazard against barrier().
*/
- asm("mrs %0, tpidr_el1" : "=r" (off) :
+ asm(ALTERNATIVE("mrs %0, tpidr_el1",
+ "mrs %0, tpidr_el2",
+ ARM64_HAS_VIRT_HOST_EXTN)
+ : "=r" (off) :
"Q" (*(const unsigned long *)current_stack_pointer));
return off;
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -32,6 +32,8 @@
#define ALT_ORIG_PTR(a) __ALT_PTR(a, orig_offset)
#define ALT_REPL_PTR(a) __ALT_PTR(a, alt_offset)
+int alternatives_applied;
+
struct alt_region {
struct alt_instr *begin;
struct alt_instr *end;
@@ -142,7 +144,6 @@ static void __apply_alternatives(void *a
*/
static int __apply_alternatives_multi_stop(void *unused)
{
- static int patched = 0;
struct alt_region region = {
.begin = (struct alt_instr *)__alt_instructions,
.end = (struct alt_instr *)__alt_instructions_end,
@@ -150,14 +151,14 @@ static int __apply_alternatives_multi_st
/* We always have a CPU 0 at this point (__init) */
if (smp_processor_id()) {
- while (!READ_ONCE(patched))
+ while (!READ_ONCE(alternatives_applied))
cpu_relax();
isb();
} else {
- BUG_ON(patched);
+ BUG_ON(alternatives_applied);
__apply_alternatives(®ion);
/* Barriers provided by the cache flushing */
- WRITE_ONCE(patched, 1);
+ WRITE_ONCE(alternatives_applied, 1);
}
return 0;
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -829,6 +829,22 @@ static int __init parse_kpti(char *str)
early_param("kpti", parse_kpti);
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
+static int cpu_copy_el2regs(void *__unused)
+{
+ /*
+ * Copy register values that aren't redirected by hardware.
+ *
+ * Before code patching, we only set tpidr_el1, all CPUs need to copy
+ * this value to tpidr_el2 before we patch the code. Once we've done
+ * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
+ * do anything here.
+ */
+ if (!alternatives_applied)
+ write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
+
+ return 0;
+}
+
static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "GIC system register CPU interface",
@@ -895,6 +911,7 @@ static const struct arm64_cpu_capabiliti
.capability = ARM64_HAS_VIRT_HOST_EXTN,
.def_scope = SCOPE_SYSTEM,
.matches = runs_at_el2,
+ .enable = cpu_copy_el2regs,
},
{
.desc = "32-bit EL0 Support",
next prev parent reply other threads:[~2018-07-20 12:31 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-20 12:13 [PATCH 4.9 00/66] 4.9.114-stable review Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 01/66] MIPS: Use async IPIs for arch_trigger_cpumask_backtrace() Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 02/66] compiler, clang: suppress warning for unused static inline functions Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 03/66] compiler, clang: properly override inline for clang Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 04/66] compiler, clang: always inline when CONFIG_OPTIMIZE_INLINING is disabled Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 05/66] compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 06/66] x86/asm: Add _ASM_ARG* constants for argument registers to <asm/asm.h> Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 07/66] x86/paravirt: Make native_save_fl() extern inline Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 08/66] ocfs2: subsystem.su_mutex is required while accessing the item->ci_parent Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 09/66] ocfs2: ip_alloc_sem should be taken in ocfs2_get_block() Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 10/66] mtd: m25p80: consider max message size in m25p80_read Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 11/66] spi/bcm63xx: make spi subsystem aware of message size limits Greg Kroah-Hartman
2018-07-20 12:34 ` Mark Brown
2018-07-20 13:39 ` Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 13/66] bcm63xx_enet: correct clock usage Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 14/66] bcm63xx_enet: do not write to random DMA channel on BCM6345 Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 15/66] crypto: crypto4xx - remove bad list_del Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 16/66] crypto: crypto4xx - fix crypto4xx_build_pdr, crypto4xx_build_sdr leak Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 17/66] atm: zatm: Fix potential Spectre v1 Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 18/66] ipvlan: fix IFLA_MTU ignored on NEWLINK Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 19/66] net: dccp: avoid crash in ccid3_hc_rx_send_feedback() Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 20/66] net: dccp: switch rx_tstamp_last_feedback to monotonic clock Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 21/66] net/mlx5: Fix incorrect raw command length parsing Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 22/66] net/mlx5: Fix wrong size allocation for QoS ETC TC regitster Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 23/66] net_sched: blackhole: tell upper qdisc about dropped packets Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 24/66] net: sungem: fix rx checksum support Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 25/66] qed: Fix use of incorrect size in memcpy call Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 26/66] qed: Limit msix vectors in kdump kernel to the minimum required count Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 28/66] r8152: napi hangup fix after disconnect Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 29/66] tcp: fix Fast Open key endianness Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 31/66] vhost_net: validate sock before trying to put its fd Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 32/66] net/packet: fix use-after-free Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 33/66] net/mlx5: Fix command interface race in polling mode Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 34/66] net: cxgb3_main: fix potential Spectre v1 Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 35/66] rtlwifi: rtl8821ae: fix firmware is not ready to run Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 36/66] net: lan78xx: Fix race in tx pending skb size calculation Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 37/66] netfilter: ebtables: reject non-bridge targets Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 38/66] reiserfs: fix buffer overflow with long warning messages Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 39/66] KEYS: DNS: fix parsing multiple options Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 40/66] netfilter: ipv6: nf_defrag: drop skb dst before queueing Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 41/66] rds: avoid unenecessary cong_update in loop transport Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.9 42/66] net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 43/66] arm64: assembler: introduce ldr_this_cpu Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 44/66] KVM: arm64: Store vcpu on the stack during __guest_enter() Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 45/66] KVM: arm/arm64: Convert kvm_host_cpu_state to a static per-cpu allocation Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 46/66] KVM: arm64: Change hyp_panic()s dependency on tpidr_el2 Greg Kroah-Hartman
2018-07-20 12:14 ` Greg Kroah-Hartman [this message]
2018-07-20 12:14 ` [PATCH 4.9 48/66] KVM: arm64: Stop save/restoring host tpidr_el1 on VHE Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 49/66] arm64: alternatives: Add dynamic patching feature Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 50/66] KVM: arm/arm64: Do not use kern_hyp_va() with kvm_vgic_global_state Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 51/66] KVM: arm64: Avoid storing the vcpu pointer on the stack Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 52/66] arm/arm64: smccc: Add SMCCC-specific return codes Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 53/66] arm64: Call ARCH_WORKAROUND_2 on transitions between EL0 and EL1 Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 54/66] arm64: Add per-cpu infrastructure to call ARCH_WORKAROUND_2 Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 55/66] arm64: Add ARCH_WORKAROUND_2 probing Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 56/66] arm64: Add ssbd command-line option Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 57/66] arm64: ssbd: Add global mitigation state accessor Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 58/66] arm64: ssbd: Skip apply_ssbd if not using dynamic mitigation Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 59/66] arm64: ssbd: Restore mitigation status on CPU resume Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 60/66] arm64: ssbd: Introduce thread flag to control userspace mitigation Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 61/66] arm64: ssbd: Add prctl interface for per-thread mitigation Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 62/66] arm64: KVM: Add HYP per-cpu accessors Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 63/66] arm64: KVM: Add ARCH_WORKAROUND_2 support for guests Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 64/66] arm64: KVM: Handle guests ARCH_WORKAROUND_2 requests Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.9 65/66] arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID Greg Kroah-Hartman
2018-07-20 13:34 ` [PATCH 4.9 00/66] 4.9.114-stable review Nathan Chancellor
2018-07-20 13:40 ` Greg Kroah-Hartman
2018-07-21 7:36 ` Naresh Kamboju
2018-07-21 13:40 ` Guenter Roeck
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