linux-kernel - [RFC PATCH 19/26] kvm: arm64: Extract __do_hyp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20201104183630.27513-20-dbrazdil@google.com>
Date:   Wed,  4 Nov 2020 18:36:23 +0000
From:   David Brazdil <dbrazdil@...gle.com>
To:     kvmarm@...ts.cs.columbia.edu
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Marc Zyngier <maz@...nel.org>,
        James Morse <james.morse@....com>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, Dennis Zhou <dennis@...nel.org>,
        Tejun Heo <tj@...nel.org>, Christoph Lameter <cl@...ux.com>,
        Mark Rutland <mark.rutland@....com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Quentin Perret <qperret@...gle.com>,
        Andrew Scull <ascull@...gle.com>, kernel-team@...roid.com,
        David Brazdil <dbrazdil@...gle.com>
Subject: [RFC PATCH 19/26] kvm: arm64: Extract __do_hyp_init into a helper function

In preparation for adding a CPU entry point in nVHE hyp code, extract
most of __do_hyp_init hypervisor initialization code into a common
helper function. This will be invoked by the entry point to install KVM
on the newly booted CPU.

Signed-off-by: David Brazdil <dbrazdil@...gle.com>
---
 arch/arm64/kvm/hyp/nvhe/hyp-init.S | 39 +++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
index 6f3ac5d428ec..1726cc44b3ee 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -68,16 +68,35 @@ __do_hyp_init:
 	mov	x0, #SMCCC_RET_NOT_SUPPORTED
 	eret
 
-1:	ldr	x0, [x1, #NVHE_INIT_TPIDR_EL2]
-	msr	tpidr_el2, x0
+1:	mov	x0, x1
+	mov	x4, lr
+	bl	___kvm_hyp_init
+	mov	lr, x4
 
-	ldr	x0, [x1, #NVHE_INIT_STACK_PTR]
-	mov	sp, x0
+	/* Hello, World! */
+	mov	x0, #SMCCC_RET_SUCCESS
+	eret
+SYM_CODE_END(__kvm_hyp_init)
+
+/*
+ * Initialize the hypervisor in EL2.
+ *
+ * Only modifies x0..x3 so as to not clobber callee-saved SMCCC registers
+ * and leave x4 for the caller.
+ *
+ * x0: struct kvm_nvhe_init_params PA
+ */
+SYM_CODE_START(___kvm_hyp_init)
+	ldr	x1, [x0, #NVHE_INIT_TPIDR_EL2]
+	msr	tpidr_el2, x1
+
+	ldr	x1, [x0, #NVHE_INIT_STACK_PTR]
+	mov	sp, x1
 
-	ldr	x0, [x1, #NVHE_INIT_VECTOR_PTR]
-	msr	vbar_el2, x0
+	ldr	x1, [x0, #NVHE_INIT_VECTOR_PTR]
+	msr	vbar_el2, x1
 
-	ldr	x1, [x1, #NVHE_INIT_PGD_PTR]
+	ldr	x1, [x0, #NVHE_INIT_PGD_PTR]
 	phys_to_ttbr x0, x1
 alternative_if ARM64_HAS_CNP
 	orr	x0, x0, #TTBR_CNP_BIT
@@ -137,10 +156,8 @@ alternative_else_nop_endif
 	msr	sctlr_el2, x0
 	isb
 
-	/* Hello, World! */
-	mov	x0, #SMCCC_RET_SUCCESS
-	eret
-SYM_CODE_END(__kvm_hyp_init)
+	ret
+SYM_CODE_END(___kvm_hyp_init)
 
 SYM_CODE_START(__kvm_handle_stub_hvc)
 	cmp	x0, #HVC_SOFT_RESTART
-- 
2.29.1.341.ge80a0c044ae-goog