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From:   David Brazdil <dbrazdil@google.com>
To:     kvmarm@lists.cs.columbia.edu
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Julien Thierry <julien.thierry.kdev@gmail.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        David Brazdil <dbrazdil@google.com>
Subject: [PATCH v2 8/8] KVM: arm64: Remove hyp_symbol_addr
Date:   Tue,  5 Jan 2021 18:05:41 +0000
Message-Id: <20210105180541.65031-9-dbrazdil@google.com>
In-Reply-To: <20210105180541.65031-1-dbrazdil@google.com>
References: <20210105180541.65031-1-dbrazdil@google.com>
MIME-Version: 1.0
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Hyp code used the hyp_symbol_addr helper to force PC-relative addressing
because absolute addressing results in kernel VAs due to the way hyp
code is linked. This is not true anymore, so remove the helper and
update all of its users.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/include/asm/kvm_asm.h         | 26 ------------------------
 arch/arm64/kvm/hyp/include/hyp/switch.h  |  4 ++--
 arch/arm64/kvm/hyp/nvhe/hyp-smp.c        |  4 ++--
 arch/arm64/kvm/hyp/nvhe/psci-relay.c     | 24 +++++++++++-----------
 arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c |  2 +-
 5 files changed, 17 insertions(+), 43 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 8a33d83ea843..22d933e9b59e 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -199,32 +199,6 @@ extern void __vgic_v3_init_lrs(void);
 
 extern u32 __kvm_get_mdcr_el2(void);
 
-#if defined(GCC_VERSION) && GCC_VERSION < 50000
-#define SYM_CONSTRAINT	"i"
-#else
-#define SYM_CONSTRAINT	"S"
-#endif
-
-/*
- * Obtain the PC-relative address of a kernel symbol
- * s: symbol
- *
- * The goal of this macro is to return a symbol's address based on a
- * PC-relative computation, as opposed to a loading the VA from a
- * constant pool or something similar. This works well for HYP, as an
- * absolute VA is guaranteed to be wrong. Only use this if trying to
- * obtain the address of a symbol (i.e. not something you obtained by
- * following a pointer).
- */
-#define hyp_symbol_addr(s)						\
-	({								\
-		typeof(s) *addr;					\
-		asm("adrp	%0, %1\n"				\
-		    "add	%0, %0, :lo12:%1\n"			\
-		    : "=r" (addr) : SYM_CONSTRAINT (&s));		\
-		addr;							\
-	})
-
 #define __KVM_EXTABLE(from, to)						\
 	"	.pushsection	__kvm_ex_table, \"a\"\n"		\
 	"	.align		3\n"					\
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 84473574c2e7..54f4860cd87c 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -505,8 +505,8 @@ static inline void __kvm_unexpected_el2_exception(void)
 	struct exception_table_entry *entry, *end;
 	unsigned long elr_el2 = read_sysreg(elr_el2);
 
-	entry = hyp_symbol_addr(__start___kvm_ex_table);
-	end = hyp_symbol_addr(__stop___kvm_ex_table);
+	entry = &__start___kvm_ex_table;
+	end = &__stop___kvm_ex_table;
 
 	while (entry < end) {
 		addr = (unsigned long)&entry->insn + entry->insn;
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
index 2997aa156d8e..879559057dee 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
@@ -33,8 +33,8 @@ unsigned long __hyp_per_cpu_offset(unsigned int cpu)
 	if (cpu >= ARRAY_SIZE(kvm_arm_hyp_percpu_base))
 		hyp_panic();
 
-	cpu_base_array = (unsigned long *)hyp_symbol_addr(kvm_arm_hyp_percpu_base);
+	cpu_base_array = (unsigned long *)&kvm_arm_hyp_percpu_base;
 	this_cpu_base = kern_hyp_va(cpu_base_array[cpu]);
-	elf_base = (unsigned long)hyp_symbol_addr(__per_cpu_start);
+	elf_base = (unsigned long)&__per_cpu_start;
 	return this_cpu_base - elf_base;
 }
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index e3947846ffcb..f254a425cb3a 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -134,8 +134,8 @@ static int psci_cpu_on(u64 func_id, struct kvm_cpu_context *host_ctxt)
 	if (cpu_id == INVALID_CPU_ID)
 		return PSCI_RET_INVALID_PARAMS;
 
-	boot_args = per_cpu_ptr(hyp_symbol_addr(cpu_on_args), cpu_id);
-	init_params = per_cpu_ptr(hyp_symbol_addr(kvm_init_params), cpu_id);
+	boot_args = per_cpu_ptr(&cpu_on_args, cpu_id);
+	init_params = per_cpu_ptr(&kvm_init_params, cpu_id);
 
 	/* Check if the target CPU is already being booted. */
 	if (!try_acquire_boot_args(boot_args))
@@ -146,7 +146,7 @@ static int psci_cpu_on(u64 func_id, struct kvm_cpu_context *host_ctxt)
 	wmb();
 
 	ret = psci_call(func_id, mpidr,
-			__hyp_pa(hyp_symbol_addr(kvm_hyp_cpu_entry)),
+			__hyp_pa(&kvm_hyp_cpu_entry),
 			__hyp_pa(init_params));
 
 	/* If successful, the lock will be released by the target CPU. */
@@ -165,8 +165,8 @@ static int psci_cpu_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
 	struct psci_boot_args *boot_args;
 	struct kvm_nvhe_init_params *init_params;
 
-	boot_args = this_cpu_ptr(hyp_symbol_addr(suspend_args));
-	init_params = this_cpu_ptr(hyp_symbol_addr(kvm_init_params));
+	boot_args = this_cpu_ptr(&suspend_args);
+	init_params = this_cpu_ptr(&kvm_init_params);
 
 	/*
 	 * No need to acquire a lock before writing to boot_args because a core
@@ -180,7 +180,7 @@ static int psci_cpu_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
 	 * point if it is a deep sleep state.
 	 */
 	return psci_call(func_id, power_state,
-			 __hyp_pa(hyp_symbol_addr(kvm_hyp_cpu_resume)),
+			 __hyp_pa(&kvm_hyp_cpu_resume),
 			 __hyp_pa(init_params));
 }
 
@@ -192,8 +192,8 @@ static int psci_system_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
 	struct psci_boot_args *boot_args;
 	struct kvm_nvhe_init_params *init_params;
 
-	boot_args = this_cpu_ptr(hyp_symbol_addr(suspend_args));
-	init_params = this_cpu_ptr(hyp_symbol_addr(kvm_init_params));
+	boot_args = this_cpu_ptr(&suspend_args);
+	init_params = this_cpu_ptr(&kvm_init_params);
 
 	/*
 	 * No need to acquire a lock before writing to boot_args because a core
@@ -204,7 +204,7 @@ static int psci_system_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
 
 	/* Will only return on error. */
 	return psci_call(func_id,
-			 __hyp_pa(hyp_symbol_addr(kvm_hyp_cpu_resume)),
+			 __hyp_pa(&kvm_hyp_cpu_resume),
 			 __hyp_pa(init_params), 0);
 }
 
@@ -213,12 +213,12 @@ asmlinkage void __noreturn kvm_host_psci_cpu_entry(bool is_cpu_on)
 	struct psci_boot_args *boot_args;
 	struct kvm_cpu_context *host_ctxt;
 
-	host_ctxt = &this_cpu_ptr(hyp_symbol_addr(kvm_host_data))->host_ctxt;
+	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
 
 	if (is_cpu_on)
-		boot_args = this_cpu_ptr(hyp_symbol_addr(cpu_on_args));
+		boot_args = this_cpu_ptr(&cpu_on_args);
 	else
-		boot_args = this_cpu_ptr(hyp_symbol_addr(suspend_args));
+		boot_args = this_cpu_ptr(&suspend_args);
 
 	cpu_reg(host_ctxt, 0) = boot_args->r0;
 	write_sysreg_el2(boot_args->pc, SYS_ELR);
diff --git a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
index 8f0585640241..87a54375bd6e 100644
--- a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
+++ b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
@@ -64,7 +64,7 @@ int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
 	}
 
 	rd = kvm_vcpu_dabt_get_rd(vcpu);
-	addr  = hyp_symbol_addr(kvm_vgic_global_state)->vcpu_hyp_va;
+	addr  = kvm_vgic_global_state.vcpu_hyp_va;
 	addr += fault_ipa - vgic->vgic_cpu_base;
 
 	if (kvm_vcpu_dabt_iswrite(vcpu)) {
-- 
2.29.2.729.g45daf8777d-goog