[PATCH kvmtool v4 6/8] KVM: arm/arm64: Back out ptrauth command-line arguments

From: Dave Martin <Dave.Martin@arm.com>
To: kvmarm@lists.cs.columbia.edu
Cc: Christoffer Dall <cdall@kernel.org>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Andre Przywara <andre.przywara@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Kristina Martsenko <kristina.martsenko@arm.com>,
	Zhang Lei <zhang.lei@jp.fujitsu.com>,
	Amit Daniel Kachhap <amit.kachhap@arm.com>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH kvmtool v4 6/8] KVM: arm/arm64: Back out ptrauth command-line arguments
Date: Fri,  7 Jun 2019 12:26:27 +0100	[thread overview]
Message-ID: <1559906789-20936-7-git-send-email-Dave.Martin@arm.com> (raw)
In-Reply-To: <1559906789-20936-1-git-send-email-Dave.Martin@arm.com>

Will says that the command-line arguments for controlling optional
vcpu features are superfluous: we don't attempt to support
migration, and this isn't QEMU.

So, remove the command-line arguments and just default pointer auth
to on if supported.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>

---

Changes since v3:

 * New patch.  This should probably be folded into the previous one.
---
 arm/aarch64/include/kvm/kvm-config-arch.h |  6 +-----
 arm/include/arm-common/kvm-config-arch.h  |  2 --
 arm/kvm-cpu.c                             | 19 ++++---------------
 3 files changed, 5 insertions(+), 22 deletions(-)

diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h
index 0279b13..04be43d 100644
--- a/arm/aarch64/include/kvm/kvm-config-arch.h
+++ b/arm/aarch64/include/kvm/kvm-config-arch.h
@@ -8,11 +8,7 @@
 			"Create PMUv3 device"),				\
 	OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed,			\
 			"Specify random seed for Kernel Address Space "	\
-			"Layout Randomization (KASLR)"),		\
-	OPT_BOOLEAN('\0', "enable-ptrauth", &(cfg)->enable_ptrauth,	\
-			"Enables pointer authentication"),		\
-	OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth,	\
-			"Disables pointer authentication"),
+			"Layout Randomization (KASLR)"),
 
 #include "arm-common/kvm-config-arch.h"
 
diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h
index 1b4287d..5734c46 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -10,8 +10,6 @@ struct kvm_config_arch {
 	bool		aarch32_guest;
 	bool		has_pmuv3;
 	u64		kaslr_seed;
-	bool		enable_ptrauth;
-	bool		disable_ptrauth;
 	enum irqchip_type irqchip;
 	u64		fw_addr;
 };
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index acd1d5f..fff8494 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -68,16 +68,9 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
 		vcpu_init.features[0] |= (1UL << KVM_ARM_VCPU_PSCI_0_2);
 	}
 
-	/* Check Pointer Authentication command line arguments. */
-	if (kvm->cfg.arch.enable_ptrauth && kvm->cfg.arch.disable_ptrauth)
-		die("Both enable-ptrauth and disable-ptrauth option cannot be present");
-	/*
-	 * Always enable Pointer Authentication if system supports
-	 * this extension unless disable-ptrauth option is present.
-	 */
+	/* Enable pointer authentication if available */
 	if (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) &&
-	    kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) &&
-	    !kvm->cfg.arch.disable_ptrauth)
+	    kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC))
 			vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE;
 
 	/*
@@ -118,12 +111,8 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
 			die("Unable to find matching target");
 	}
 
-	if (err || target->init(vcpu)) {
-		if (kvm->cfg.arch.enable_ptrauth)
-			die("Unable to initialise vcpu with pointer authentication feature");
-		else
-			die("Unable to initialise vcpu");
-	}
+	if (err || target->init(vcpu))
+		die("Unable to initialise vcpu");
 
 	coalesced_offset = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION,
 				 KVM_CAP_COALESCED_MMIO);
-- 
2.1.4

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