From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <maz@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>
Subject: [PATCH] arm64: KVM: Invoke compute_layout() before alternatives are applied
Date: Wed, 16 Oct 2019 18:59:53 +0200 [thread overview]
Message-ID: <20191016165953.o6ogh4fdmsjmd2sw@linutronix.de> (raw)
compute_layout() is invoked as part of an alternative fixup under
stop_machine(). This function invokes get_random_long() which acquires a
sleeping lock on -RT which can not be acquired in this context.
Rename compute_layout() to kvm_compute_layout() and invoke it before
stop_machines() invokes the fixups. Add a __init prefix to
kvm_compute_layout() because the caller has it, too (and so the code can
be discarded after boot).
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/arm64/include/asm/alternative.h | 6 ++++++
arch/arm64/kernel/alternative.c | 1 +
arch/arm64/kvm/va_layout.c | 11 ++++-------
3 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index b9f8d787eea9f..7532f044d713b 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -35,6 +35,12 @@ void apply_alternatives_module(void *start, size_t length);
static inline void apply_alternatives_module(void *start, size_t length) { }
#endif
+#ifdef CONFIG_KVM_ARM_HOST
+void kvm_compute_layout(void);
+#else
+static inline void kvm_compute_layout(void) { }
+#endif
+
#define ALTINSTR_ENTRY(feature,cb) \
" .word 661b - .\n" /* label */ \
" .if " __stringify(cb) " == 0\n" \
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index d1757ef1b1e74..c28652ee06f64 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -238,6 +238,7 @@ static int __apply_alternatives_multi_stop(void *unused)
void __init apply_alternatives_all(void)
{
/* better not try code patching on a live SMP system */
+ kvm_compute_layout();
stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask);
}
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index 2cf7d4b606c38..0b9fbdf0aaddd 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -22,12 +22,15 @@ static u8 tag_lsb;
static u64 tag_val;
static u64 va_mask;
-static void compute_layout(void)
+__init void kvm_compute_layout(void)
{
phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);
u64 hyp_va_msb;
int kva_msb;
+ if (WARN_ON(va_mask))
+ return;
+
/* Where is my RAM region? */
hyp_va_msb = idmap_addr & BIT(vabits_actual - 1);
hyp_va_msb ^= BIT(vabits_actual - 1);
@@ -110,9 +113,6 @@ void __init kvm_update_va_mask(struct alt_instr *alt,
BUG_ON(nr_inst != 5);
- if (!has_vhe() && !va_mask)
- compute_layout();
-
for (i = 0; i < nr_inst; i++) {
u32 rd, rn, insn, oinsn;
@@ -156,9 +156,6 @@ void kvm_patch_vector_branch(struct alt_instr *alt,
return;
}
- if (!va_mask)
- compute_layout();
-
/*
* Compute HYP VA by using the same computation as kern_hyp_va()
*/
--
2.23.0
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next reply other threads:[~2019-10-16 17:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 16:59 Sebastian Andrzej Siewior [this message]
2019-10-17 17:41 ` [PATCH] arm64: KVM: Invoke compute_layout() before alternatives are applied James Morse
2019-11-28 19:58 ` [PATCH v2] " Sebastian Andrzej Siewior
2019-12-06 11:22 ` Marc Zyngier
2019-12-06 11:46 ` Catalin Marinas
2019-12-06 11:57 ` Catalin Marinas
2019-12-06 12:12 ` Marc Zyngier
2019-12-06 12:21 ` Catalin Marinas
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