From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Jing Zhang <jingzhangos@google.com>,
Prasad Sodagudi <psodagud@codeaurora.org>,
Srinivas Ramana <sramana@codeaurora.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
James Morse <james.morse@arm.com>,
Ajay Patil <pajay@qti.qualcomm.com>,
kernel-team@android.com, David Brazdil <dbrazdil@google.com>,
Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH v3 09/21] arm64: cpufeature: Add global feature override facility
Date: Mon, 11 Jan 2021 13:27:59 +0000 [thread overview]
Message-ID: <20210111132811.2455113-10-maz@kernel.org> (raw)
In-Reply-To: <20210111132811.2455113-1-maz@kernel.org>
Add a facility to globally override a feature, no matter what
the HW says. Yes, this is dangerous.
Nothing uses this yet, so we are pretty safe. For now.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/cpufeature.h | 2 ++
arch/arm64/kernel/cpufeature.c | 26 +++++++++++++++++++++-----
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 9a555809b89c..465d2cb63bfc 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -75,6 +75,8 @@ struct arm64_ftr_reg {
u64 sys_val;
u64 user_val;
const struct arm64_ftr_bits *ftr_bits;
+ u64 *override_val;
+ u64 *override_mask;
};
extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0;
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index e99eddec0a46..492321054bd5 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -544,13 +544,17 @@ static const struct arm64_ftr_bits ftr_raz[] = {
ARM64_FTR_END,
};
-#define ARM64_FTR_REG(id, table) { \
- .sys_id = id, \
- .reg = &(struct arm64_ftr_reg){ \
- .name = #id, \
- .ftr_bits = &((table)[0]), \
+#define ARM64_FTR_REG_OVERRIDE(id, table, v, m) { \
+ .sys_id = id, \
+ .reg = &(struct arm64_ftr_reg){ \
+ .name = #id, \
+ .ftr_bits = &((table)[0]), \
+ .override_val = v, \
+ .override_mask = m, \
}}
+#define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, NULL, NULL)
+
static const struct __ftr_reg_entry {
u32 sys_id;
struct arm64_ftr_reg *reg;
@@ -786,6 +790,18 @@ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
val &= valid_mask;
+ if (reg->override_mask && reg->override_val) {
+ u64 override = val;
+ override &= ~*reg->override_mask;
+ override |= (*reg->override_val & *reg->override_mask);
+
+ if (val != override)
+ pr_warn("%s: forced from %016llx to %016llx\n",
+ reg->name, val, override);
+
+ val = override;
+ }
+
reg->sys_val = val;
reg->strict_mask = strict_mask;
reg->user_mask = user_mask;
--
2.29.2
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next prev parent reply other threads:[~2021-01-11 13:30 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 13:27 [PATCH v3 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 01/21] arm64: Fix labels in el2_setup macros Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 02/21] arm64: Fix outdated TCR setup comment Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 03/21] arm64: Turn the MMU-on sequence into a macro Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 04/21] arm64: Provide an 'upgrade to VHE' stub hypercall Marc Zyngier
2021-01-11 13:53 ` Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 05/21] arm64: Initialise as nVHE before switching to VHE Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 06/21] arm64: Move VHE-specific SPE setup to mutate_to_vhe() Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 07/21] arm64: Simplify init_el2_state to be non-VHE only Marc Zyngier
2021-01-11 13:27 ` [PATCH v3 08/21] arm64: Move SCTLR_EL1 initialisation to EL-agnostic code Marc Zyngier
2021-01-11 13:27 ` Marc Zyngier [this message]
2021-01-11 18:41 ` [PATCH v3 09/21] arm64: cpufeature: Add global feature override facility Catalin Marinas
2021-01-11 19:48 ` Marc Zyngier
2021-01-12 9:17 ` Suzuki K Poulose
2021-01-12 11:50 ` Marc Zyngier
2021-01-12 11:51 ` Marc Zyngier
2021-01-12 12:20 ` Suzuki K Poulose
2021-01-12 11:59 ` Suzuki K Poulose
2021-01-12 14:54 ` Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 10/21] arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 11/21] arm64: Extract early FDT mapping from kaslr_early_init() Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 13/21] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 14/21] arm64: Honor VHE being disabled from the command-line Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 15/21] arm64: Add an aliasing facility for the idreg override Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 16/21] arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 17/21] KVM: arm64: Document HVC_VHE_RESTART stub hypercall Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 18/21] arm64: Move "nokaslr" over to the early cpufeature infrastructure Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 19/21] arm64: cpufeatures: Allow disabling of BTI from the command-line Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 20/21] arm64: Defer enabling pointer authentication on boot core Marc Zyngier
2021-01-11 13:28 ` [PATCH v3 21/21] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Marc Zyngier
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