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From: David Brazdil <dbrazdil@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: Mark Rutland <mark.rutland@arm.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	kernel-team@android.com, Jonathan Corbet <corbet@lwn.net>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Sudeep Holla <sudeep.holla@arm.com>,
	James Morse <james.morse@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	Marc Zyngier <maz@kernel.org>, Tejun Heo <tj@kernel.org>,
	Dennis Zhou <dennis@kernel.org>, Christoph Lameter <cl@linux.com>,
	David Brazdil <dbrazdil@google.com>,
	Will Deacon <will@kernel.org>,
	Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH v4 10/26] kvm: arm64: Move hyp-init params to a per-CPU struct
Date: Wed,  2 Dec 2020 18:41:06 +0000	[thread overview]
Message-ID: <20201202184122.26046-11-dbrazdil@google.com> (raw)
In-Reply-To: <20201202184122.26046-1-dbrazdil@google.com>

Once we start initializing KVM on newly booted cores before the rest of
the kernel, parameters to __do_hyp_init will need to be provided by EL2
rather than EL1. At that point it will not be possible to pass its three
arguments directly because PSCI_CPU_ON only supports one context
argument.

Refactor __do_hyp_init to accept its parameters in a struct. This
prepares the code for KVM booting cores as well as removes any limits on
the number of __do_hyp_init arguments.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/include/asm/kvm_asm.h   |  6 ++++++
 arch/arm64/include/asm/kvm_hyp.h   |  2 +-
 arch/arm64/kernel/asm-offsets.c    |  3 +++
 arch/arm64/kvm/arm.c               | 23 +++++++++++++----------
 arch/arm64/kvm/hyp/nvhe/hyp-init.S | 16 +++++++---------
 arch/arm64/kvm/hyp/nvhe/hyp-main.c |  2 ++
 6 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 531f9d04eefd..1a7b91534a16 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -148,6 +148,12 @@ extern void *__vhe_undefined_symbol;
 
 #endif
 
+struct kvm_nvhe_init_params {
+	unsigned long tpidr_el2;
+	unsigned long stack_hyp_va;
+	phys_addr_t pgd_pa;
+};
+
 /* Translate a kernel address @ptr into its equivalent linear mapping */
 #define kvm_ksym_ref(ptr)						\
 	({								\
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 6b664de5ec1f..cb25c15e3d8d 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -14,6 +14,7 @@
 
 DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
 DECLARE_PER_CPU(unsigned long, kvm_hyp_vector);
+DECLARE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
 
 #define read_sysreg_elx(r,nvh,vh)					\
 	({								\
@@ -98,4 +99,3 @@ void __noreturn __hyp_do_panic(bool restore_host, u64 spsr, u64 elr, u64 par);
 #endif
 
 #endif /* __ARM64_KVM_HYP_H__ */
-
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 7d32fc959b1a..8d6272a01a00 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -110,6 +110,9 @@ int main(void)
   DEFINE(CPU_APGAKEYLO_EL1,	offsetof(struct kvm_cpu_context, sys_regs[APGAKEYLO_EL1]));
   DEFINE(HOST_CONTEXT_VCPU,	offsetof(struct kvm_cpu_context, __hyp_running_vcpu));
   DEFINE(HOST_DATA_CONTEXT,	offsetof(struct kvm_host_data, host_ctxt));
+  DEFINE(NVHE_INIT_TPIDR_EL2,	offsetof(struct kvm_nvhe_init_params, tpidr_el2));
+  DEFINE(NVHE_INIT_STACK_HYP_VA,	offsetof(struct kvm_nvhe_init_params, stack_hyp_va));
+  DEFINE(NVHE_INIT_PGD_PA,	offsetof(struct kvm_nvhe_init_params, pgd_pa));
 #endif
 #ifdef CONFIG_CPU_PM
   DEFINE(CPU_CTX_SP,		offsetof(struct cpu_suspend_ctx, sp));
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9e5d0ea84822..93a408c00249 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -51,6 +51,7 @@ DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
 
 static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
 unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
+DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
 
 /* The VMID used in the VTTBR */
 static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
@@ -1384,9 +1385,7 @@ static int kvm_init_vector_slots(void)
 
 static void cpu_init_hyp_mode(void)
 {
-	phys_addr_t pgd_ptr;
-	unsigned long hyp_stack_ptr;
-	unsigned long tpidr_el2;
+	struct kvm_nvhe_init_params *params = this_cpu_ptr_nvhe_sym(kvm_init_params);
 	struct arm_smccc_res res;
 
 	/* Switch from the HYP stub to our own HYP init vector */
@@ -1397,12 +1396,17 @@ static void cpu_init_hyp_mode(void)
 	 * kernel's mapping to the linear mapping, and store it in tpidr_el2
 	 * so that we can use adr_l to access per-cpu variables in EL2.
 	 */
-	tpidr_el2 = (unsigned long)this_cpu_ptr_nvhe_sym(__per_cpu_start) -
-		    (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
+	params->tpidr_el2 = (unsigned long)this_cpu_ptr_nvhe_sym(__per_cpu_start) -
+			    (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
 
-	pgd_ptr = kvm_mmu_get_httbr();
-	hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
-	hyp_stack_ptr = kern_hyp_va(hyp_stack_ptr);
+	params->stack_hyp_va = kern_hyp_va(__this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE);
+	params->pgd_pa = kvm_mmu_get_httbr();
+
+	/*
+	 * Flush the init params from the data cache because the struct will
+	 * be read while the MMU is off.
+	 */
+	kvm_flush_dcache_to_poc(params, sizeof(*params));
 
 	/*
 	 * Call initialization code, and switch to the full blown HYP code.
@@ -1411,8 +1415,7 @@ static void cpu_init_hyp_mode(void)
 	 * cpus_have_const_cap() wrapper.
 	 */
 	BUG_ON(!system_capabilities_finalized());
-	arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init),
-			  pgd_ptr, tpidr_el2, hyp_stack_ptr, &res);
+	arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res);
 	WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
 
 	/*
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
index 931a8c38f085..e712e317337c 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -47,9 +47,7 @@ __invalid:
 
 	/*
 	 * x0: SMCCC function ID
-	 * x1: HYP pgd
-	 * x2: per-CPU offset
-	 * x3: HYP stack
+	 * x1: struct kvm_nvhe_init_params PA
 	 */
 __do_hyp_init:
 	/* Check for a stub HVC call */
@@ -70,10 +68,13 @@ __do_hyp_init:
 	mov	x0, #SMCCC_RET_NOT_SUPPORTED
 	eret
 
-1:
-	/* Set tpidr_el2 for use by HYP to free a register */
-	msr	tpidr_el2, x2
+1:	ldr	x0, [x1, #NVHE_INIT_TPIDR_EL2]
+	msr	tpidr_el2, x0
 
+	ldr	x0, [x1, #NVHE_INIT_STACK_HYP_VA]
+	mov	sp, x0
+
+	ldr	x1, [x1, #NVHE_INIT_PGD_PA]
 	phys_to_ttbr x0, x1
 alternative_if ARM64_HAS_CNP
 	orr	x0, x0, #TTBR_CNP_BIT
@@ -133,9 +134,6 @@ alternative_else_nop_endif
 	msr	sctlr_el2, x0
 	isb
 
-	/* Set the stack */
-	mov	sp, x3
-
 	/* Set the host vector */
 	ldr	x0, =__kvm_hyp_host_vector
 	kimg_hyp_va x0, x1
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 82df7fc24760..a4f1cac714d7 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -16,6 +16,8 @@
 #define DECLARE_REG(type, name, ctxt, reg)	\
 				type name = (type)cpu_reg(ctxt, (reg))
 
+DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
+
 static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
-- 
2.29.2.454.gaff20da3a2-goog


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  parent reply	other threads:[~2020-12-02 18:44 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-02 18:40 [PATCH v4 00/26] Opt-in always-on nVHE hypervisor David Brazdil
2020-12-02 18:40 ` [PATCH v4 01/26] kvm: arm64: Add kvm-arm.mode early kernel parameter David Brazdil
2020-12-02 18:40 ` [PATCH v4 02/26] kvm: arm64: Add ARM64_KVM_PROTECTED_MODE CPU capability David Brazdil
2020-12-02 18:40 ` [PATCH v4 03/26] psci: Support psci_ops.get_version for v0.1 David Brazdil
2020-12-02 18:41 ` [PATCH v4 04/26] psci: Split functions to v0.1 and v0.2+ variants David Brazdil
2020-12-03 10:42   ` Mark Rutland
2020-12-02 18:41 ` [PATCH v4 05/26] psci: Replace psci_function_id array with a struct David Brazdil
2020-12-03 10:43   ` Mark Rutland
2020-12-02 18:41 ` [PATCH v4 06/26] psci: Add accessor for psci_0_1_function_ids David Brazdil
2020-12-03 10:47   ` Mark Rutland
2020-12-03 10:51     ` David Brazdil
2020-12-02 18:41 ` [PATCH v4 07/26] arm64: Make cpu_logical_map() take unsigned int David Brazdil
2020-12-02 18:41 ` [PATCH v4 08/26] arm64: Extract parts of el2_setup into a macro David Brazdil
2020-12-02 18:41 ` [PATCH v4 09/26] kvm: arm64: Remove vector_ptr param of hyp-init David Brazdil
2020-12-02 18:41 ` David Brazdil [this message]
2020-12-02 18:41 ` [PATCH v4 11/26] kvm: arm64: Init MAIR/TCR_EL2 from params struct David Brazdil
2020-12-02 18:41 ` [PATCH v4 12/26] kvm: arm64: Add .hyp.data..ro_after_init ELF section David Brazdil
2020-12-02 18:41 ` [PATCH v4 13/26] kvm: arm64: Support per_cpu_ptr in nVHE hyp code David Brazdil
2020-12-02 18:41 ` [PATCH v4 14/26] kvm: arm64: Create nVHE copy of cpu_logical_map David Brazdil
2020-12-02 18:41 ` [PATCH v4 15/26] kvm: arm64: Add SMC handler in nVHE EL2 David Brazdil
2020-12-03 13:31   ` Marc Zyngier
2020-12-02 18:41 ` [PATCH v4 16/26] kvm: arm64: Bootstrap PSCI " David Brazdil
2020-12-03 10:55   ` Mark Rutland
2020-12-03 13:46   ` Marc Zyngier
2020-12-02 18:41 ` [PATCH v4 17/26] kvm: arm64: Add offset for hyp VA <-> PA conversion David Brazdil
2020-12-07 22:29   ` Qian Cai
2020-12-08 10:08     ` David Brazdil
2020-12-02 18:41 ` [PATCH v4 18/26] kvm: arm64: Forward safe PSCI SMCs coming from host David Brazdil
2020-12-02 18:41 ` [PATCH v4 19/26] kvm: arm64: Extract __do_hyp_init into a helper function David Brazdil
2020-12-02 18:41 ` [PATCH v4 20/26] kvm: arm64: Add function to enter host from KVM nVHE hyp code David Brazdil
2020-12-02 18:41 ` [PATCH v4 21/26] kvm: arm64: Intercept host's CPU_ON SMCs David Brazdil
2020-12-02 18:41 ` [PATCH v4 22/26] kvm: arm64: Intercept host's CPU_SUSPEND PSCI SMCs David Brazdil
2020-12-02 18:41 ` [PATCH v4 23/26] kvm: arm64: Intercept host's SYSTEM_SUSPEND " David Brazdil
2020-12-02 18:41 ` [PATCH v4 24/26] kvm: arm64: Keep nVHE EL2 vector installed David Brazdil
2020-12-02 18:41 ` [PATCH v4 25/26] kvm: arm64: Trap host SMCs in protected mode David Brazdil
2020-12-02 18:41 ` [PATCH v4 26/26] kvm: arm64: Fix EL2 mode availability checks David Brazdil
2020-12-03 19:23 ` [PATCH v4 00/26] Opt-in always-on nVHE hypervisor Marc Zyngier
2020-12-08 19:14   ` David Brazdil
2020-12-08 20:12     ` Marc Zyngier

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