From 23fa18eaa71266feff7ba8d83022d9e1cc83c65a Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:42:03 +0000
Subject: [PATCH] disable pwm7

---
 kernel/arch/arm64/kvm/hyp/entry.S |  145 +++++++++++++++++++++++++++---------------------
 1 files changed, 81 insertions(+), 64 deletions(-)

diff --git a/kernel/arch/arm64/kvm/hyp/entry.S b/kernel/arch/arm64/kvm/hyp/entry.S
index 9d397f0..e831d3d 100644
--- a/kernel/arch/arm64/kvm/hyp/entry.S
+++ b/kernel/arch/arm64/kvm/hyp/entry.S
@@ -1,79 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (C) 2015 - ARM Ltd
  * Author: Marc Zyngier <marc.zyngier@arm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <linux/linkage.h>
 
 #include <asm/alternative.h>
-#include <asm/asm-offsets.h>
 #include <asm/assembler.h>
 #include <asm/fpsimdmacros.h>
 #include <asm/kvm.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmu.h>
-
-#define CPU_GP_REG_OFFSET(x)	(CPU_GP_REGS + x)
-#define CPU_XREG_OFFSET(x)	CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x)
+#include <asm/kvm_ptrauth.h>
 
 	.text
-	.pushsection	.hyp.text, "ax"
 
 /*
- * We treat x18 as callee-saved as the host may use it as a platform
- * register (e.g. for shadow call stack).
+ * u64 __guest_enter(struct kvm_vcpu *vcpu);
  */
-.macro save_callee_saved_regs ctxt
-	str	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
-	stp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
-	stp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
-	stp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
-	stp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
-	stp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
-	stp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
-.endm
-
-.macro restore_callee_saved_regs ctxt
-	// We require \ctxt is not x18-x28
-	ldr	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
-	ldp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
-	ldp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
-	ldp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
-	ldp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
-	ldp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
-	ldp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
-.endm
-
-/*
- * u64 __guest_enter(struct kvm_vcpu *vcpu,
- *		     struct kvm_cpu_context *host_ctxt);
- */
-ENTRY(__guest_enter)
+SYM_FUNC_START(__guest_enter)
 	// x0: vcpu
-	// x1: host context
-	// x2-x17: clobbered by macros
+	// x1-x17: clobbered by macros
 	// x29: guest context
 
-	// Store the host regs
+	adr_this_cpu x1, kvm_hyp_ctxt, x2
+
+	// Store the hyp regs
 	save_callee_saved_regs x1
 
-	// Now the host state is stored if we have a pending RAS SError it must
-	// affect the host. If any asynchronous exception is pending we defer
-	// the guest entry. The DSB isn't necessary before v8.2 as any SError
-	// would be fatal.
+	// Save hyp's sp_el0
+	save_sp_el0	x1, x2
+
+	// Now the hyp state is stored if we have a pending RAS SError it must
+	// affect the host or hyp. If any asynchronous exception is pending we
+	// defer the guest entry. The DSB isn't necessary before v8.2 as any
+	// SError would be fatal.
 alternative_if ARM64_HAS_RAS_EXTN
 	dsb	nshst
 	isb
@@ -84,7 +47,19 @@
 	ret
 
 1:
+	set_loaded_vcpu x0, x1, x2
+
 	add	x29, x0, #VCPU_CONTEXT
+
+	// Macro ptrauth_switch_to_guest format:
+	// 	ptrauth_switch_to_guest(guest cxt, tmp1, tmp2, tmp3)
+	// The below macro to restore guest keys is not implemented in C code
+	// as it may cause Pointer Authentication key signing mismatch errors
+	// when this feature is enabled for kernel code.
+	ptrauth_switch_to_guest x29, x0, x1, x2
+
+	// Restore the guest's sp_el0
+	restore_sp_el0 x29, x0
 
 	// Restore guest regs x0-x17
 	ldp	x0, x1,   [x29, #CPU_XREG_OFFSET(0)]
@@ -103,9 +78,30 @@
 	// Do not touch any register after this!
 	eret
 	sb
-ENDPROC(__guest_enter)
 
-ENTRY(__guest_exit)
+SYM_INNER_LABEL(__guest_exit_panic, SYM_L_GLOBAL)
+	// x2-x29,lr: vcpu regs
+	// vcpu x0-x1 on the stack
+
+	// If the hyp context is loaded, go straight to hyp_panic
+	get_loaded_vcpu x0, x1
+	cbnz	x0, 1f
+	b	hyp_panic
+
+1:
+	// The hyp context is saved so make sure it is restored to allow
+	// hyp_panic to run at hyp and, subsequently, panic to run in the host.
+	// This makes use of __guest_exit to avoid duplication but sets the
+	// return address to tail call into hyp_panic. As a side effect, the
+	// current state is saved to the guest context but it will only be
+	// accurate if the guest had been completely restored.
+	adr_this_cpu x0, kvm_hyp_ctxt, x1
+	adr_l	x1, hyp_panic
+	str	x1, [x0, #CPU_XREG_OFFSET(30)]
+
+	get_vcpu_ptr	x1, x0
+
+SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL)
 	// x0: return code
 	// x1: vcpu
 	// x2-x29,lr: vcpu regs
@@ -134,15 +130,30 @@
 	// Store the guest regs x18-x29, lr
 	save_callee_saved_regs x1
 
-	get_host_ctxt	x2, x3
+	// Store the guest's sp_el0
+	save_sp_el0	x1, x2
 
-	// Now restore the host regs
+	adr_this_cpu x2, kvm_hyp_ctxt, x3
+
+	// Macro ptrauth_switch_to_hyp format:
+	// 	ptrauth_switch_to_hyp(guest cxt, host cxt, tmp1, tmp2, tmp3)
+	// The below macro to save/restore keys is not implemented in C code
+	// as it may cause Pointer Authentication key signing mismatch errors
+	// when this feature is enabled for kernel code.
+	ptrauth_switch_to_hyp x1, x2, x3, x4, x5
+
+	// Restore hyp's sp_el0
+	restore_sp_el0 x2, x3
+
+	// Now restore the hyp regs
 	restore_callee_saved_regs x2
+
+	set_loaded_vcpu xzr, x2, x3
 
 alternative_if ARM64_HAS_RAS_EXTN
 	// If we have the RAS extensions we can consume a pending error
-	// without an unmask-SError and isb.
-	esb
+	// without an unmask-SError and isb. The ESB-instruction consumed any
+	// pending guest error when we took the exception from the guest.
 	mrs_s	x2, SYS_DISR_EL1
 	str	x2, [x1, #(VCPU_FAULT_DISR - VCPU_CONTEXT)]
 	cbz	x2, 1f
@@ -150,8 +161,16 @@
 	orr	x0, x0, #(1<<ARM_EXIT_WITH_SERROR_BIT)
 1:	ret
 alternative_else
-	// If we have a pending asynchronous abort, now is the
-	// time to find out. From your VAXorcist book, page 666:
+	dsb	sy		// Synchronize against in-flight ld/st
+	isb			// Prevent an early read of side-effect free ISR
+	mrs	x2, isr_el1
+	tbnz	x2, #8, 2f	// ISR_EL1.A
+	ret
+	nop
+2:
+alternative_endif
+	// We know we have a pending asynchronous abort, now is the
+	// time to flush it out. From your VAXorcist book, page 666:
 	// "Threaten me not, oh Evil one!  For I speak with
 	// the power of DEC, and I command thee to show thyself!"
 	mrs	x2, elr_el2
@@ -159,10 +178,7 @@
 	mrs	x4, spsr_el2
 	mov	x5, x0
 
-	dsb	sy		// Synchronize against in-flight ld/st
-	nop
 	msr	daifclr, #4	// Unmask aborts
-alternative_endif
 
 	// This is our single instruction exception window. A pending
 	// SError is guaranteed to occur at the earliest when we unmask
@@ -172,6 +188,7 @@
 	isb
 
 abort_guest_exit_end:
+
 	msr	daifset, #4	// Mask aborts
 	ret
 
@@ -188,4 +205,4 @@
 	msr	spsr_el2, x4
 	orr	x0, x0, x5
 1:	ret
-ENDPROC(__guest_exit)
+SYM_FUNC_END(__guest_enter)

--
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