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From: Marc Zyngier <marc.zyngier@arm.com>
To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
	kvmarm@lists.cs.columbia.edu
Cc: Russell King <linux@arm.linux.org.uk>,
	Christoffer Dall <christoffer.dall@linaro.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	James Morse <james.morse@arm.com>
Subject: [PATCH 01/20] arm64: hyp-stub: Implement HVC_RESET_VECTORS stub hypercall
Date: Fri, 17 Feb 2017 15:44:10 +0000	[thread overview]
Message-ID: <20170217154429.5000-2-marc.zyngier@arm.com> (raw)
In-Reply-To: <20170217154429.5000-1-marc.zyngier@arm.com>

Let's define a new stub hypercall that resets the HYP configuration
to its default: hyp-stub vectors, and MMU disabled.

Of course, for the hyp-stub itself, this is a trivial no-op.
Hypervisors will have a bit more work to do.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/include/asm/virt.h |  8 ++++++++
 arch/arm64/kernel/hyp-stub.S  | 13 ++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 439f6b5d31f6..6d085a4d6cf1 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -39,6 +39,14 @@
  */
 #define HVC_SOFT_RESTART 2
 
+/*
+ * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
+ */
+#define HVC_RESET_VECTORS 3
+
+/* Max number of HYP stub hypercalls */
+#define HVC_STUB_HCALL_NR 4
+
 #define BOOT_CPU_MODE_EL1	(0xe11)
 #define BOOT_CPU_MODE_EL2	(0xe12)
 
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index d3b5f75e652e..a162182d5662 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -79,8 +79,11 @@ el1_sync:
 	mov	x1, x3
 	br	x4				// no return
 
+3:	cmp	x0, #HVC_RESET_VECTORS
+	beq	9f				// Nothing to reset!
+
 	/* Someone called kvm_call_hyp() against the hyp-stub... */
-3:	mov	x0, #ARM_EXCEPTION_HYP_GONE
+	mov	x0, #ARM_EXCEPTION_HYP_GONE
 
 9:	eret
 ENDPROC(el1_sync)
@@ -137,3 +140,11 @@ ENTRY(__hyp_set_vectors)
 	ldr	lr, [sp], #16
 	ret
 ENDPROC(__hyp_set_vectors)
+
+ENTRY(__hyp_reset_vectors)
+	str	lr, [sp, #-16]!
+	mov	x0, #HVC_RESET_VECTORS
+	hvc	#0
+	ldr	lr, [sp], #16
+	ret
+ENDPROC(__hyp_reset_vectors)
-- 
2.11.0

  reply	other threads:[~2017-02-17 15:44 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-17 15:44 [PATCH 00/20] arm/arm64: KVM: Rework the hyp-stub API Marc Zyngier
2017-02-17 15:44 ` Marc Zyngier [this message]
2017-02-17 15:44 ` [PATCH 02/20] arm64: KVM: Implement HVC_RESET_VECTORS stub hypercall Marc Zyngier
2017-02-20 16:54   ` James Morse
2017-02-17 15:44 ` [PATCH 03/20] arm64: KVM: Implement HVC_GET_VECTORS in the init code Marc Zyngier
2017-02-17 15:44 ` [PATCH 04/20] arm64: KVM: Allow the main HYP code to use the init hyp stub implementation Marc Zyngier
2017-02-17 15:44 ` [PATCH 05/20] arm64: KVM: Convert __cpu_reset_hyp_mode to using __hyp_reset_vectors Marc Zyngier
2017-02-17 15:44 ` [PATCH 06/20] arm64: KVM: Implement HVC_SOFT_RESTART in the init code Marc Zyngier
2017-02-17 15:44 ` [PATCH 07/20] ARM: hyp-stub: improve ABI Marc Zyngier
2017-02-17 15:44 ` [PATCH 08/20] ARM: soft-reboot into same mode that we entered the kernel Marc Zyngier
2017-02-17 15:44 ` [PATCH 09/20] ARM: KVM: Convert KVM to use HVC_GET_VECTORS Marc Zyngier
2017-02-17 15:44 ` [PATCH 10/20] ARM: hyp-stub: Use r1 for the soft-restart address Marc Zyngier
2017-02-19  8:22   ` Ard Biesheuvel
2017-02-19 11:09     ` Marc Zyngier
2017-02-17 15:44 ` [PATCH 11/20] ARM: Expose the VA/IDMAP offset Marc Zyngier
2017-02-17 15:44 ` [PATCH 12/20] ARM: hyp-stub: Implement HVC_RESET_VECTORS stub hypercall Marc Zyngier
2017-02-17 15:44 ` [PATCH 13/20] ARM: KVM: " Marc Zyngier
2017-02-19  8:07   ` Ard Biesheuvel
2017-02-19 11:19     ` Marc Zyngier
2017-02-19 11:42   ` Ard Biesheuvel
2017-02-17 15:44 ` [PATCH 14/20] ARM: KVM: Implement HVC_GET_VECTORS in the init code Marc Zyngier
2017-02-17 15:44 ` [PATCH 15/20] ARM: KVM: Allow the main HYP code to use the init hyp stub implementation Marc Zyngier
2017-02-17 15:44 ` [PATCH 16/20] ARM: KVM: Convert __cpu_reset_hyp_mode to using __hyp_reset_vectors Marc Zyngier
2017-02-17 15:44 ` [PATCH 17/20] ARM: KVM: Implement HVC_SOFT_RESTART in the init code Marc Zyngier
2017-02-17 15:44 ` [PATCH 18/20] arm/arm64: KVM: Simplify __cpu_reset_hyp_mode Marc Zyngier
2017-02-17 15:44 ` [PATCH 19/20] arm/arm64: KVM: Remove kvm_get_idmap_start Marc Zyngier
2017-02-17 15:44 ` [PATCH 20/20] arm/arm64: Add hyp-stub API documentation Marc Zyngier

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