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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 16/26] kvm: arm64: Bootstrap PSCI SMC handler in nVHE EL2
Date: Wed,  2 Dec 2020 18:41:12 +0000	[thread overview]
Message-ID: <20201202184122.26046-17-dbrazdil@google.com> (raw)
In-Reply-To: <20201202184122.26046-1-dbrazdil@google.com>

Add a handler of PSCI SMCs in nVHE hyp code. The handler is initialized
with the version used by the host's PSCI driver and the function IDs it
was configured with. If the SMC function ID matches one of the
configured PSCI calls (for v0.1) or falls into the PSCI function ID
range (for v0.2+), the SMC is handled by the PSCI handler. For now, all
SMCs return PSCI_RET_NOT_SUPPORTED.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/include/asm/kvm_hyp.h              |   2 +
 arch/arm64/kvm/arm.c                          |  25 ++++-
 .../arm64/kvm/hyp/include/nvhe/trap_handler.h |  18 ++++
 arch/arm64/kvm/hyp/nvhe/Makefile              |   2 +-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c            |  10 +-
 arch/arm64/kvm/hyp/nvhe/psci-relay.c          | 100 ++++++++++++++++++
 6 files changed, 151 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/include/nvhe/trap_handler.h
 create mode 100644 arch/arm64/kvm/hyp/nvhe/psci-relay.c

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index cb25c15e3d8d..c0450828378b 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -93,6 +93,8 @@ void deactivate_traps_vhe_put(void);
 
 u64 __guest_enter(struct kvm_vcpu *vcpu);
 
+bool kvm_host_psci_handler(struct kvm_cpu_context *host_ctxt);
+
 void __noreturn hyp_panic(void);
 #ifdef __KVM_NVHE_HYPERVISOR__
 void __noreturn __hyp_do_panic(bool restore_host, u64 spsr, u64 elr, u64 par);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 09bb4098502b..fda7bfa440d5 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -19,6 +19,7 @@
 #include <linux/kvm_irqfd.h>
 #include <linux/irqbypass.h>
 #include <linux/sched/stat.h>
+#include <linux/psci.h>
 #include <trace/events/kvm.h>
 
 #define CREATE_TRACE_POINTS
@@ -64,6 +65,8 @@ static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
 DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
 
 extern u64 kvm_nvhe_sym(__cpu_logical_map)[NR_CPUS];
+extern u32 kvm_nvhe_sym(kvm_host_psci_version);
+extern struct psci_0_1_function_ids kvm_nvhe_sym(kvm_host_psci_0_1_function_ids);
 
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 {
@@ -1600,6 +1603,22 @@ static void init_cpu_logical_map(void)
 		kvm_nvhe_sym(__cpu_logical_map)[cpu] = cpu_logical_map(cpu);
 }
 
+static bool init_psci_relay(void)
+{
+	/*
+	 * If PSCI has not been initialized, protected KVM cannot install
+	 * itself on newly booted CPUs.
+	 */
+	if (!psci_ops.get_version) {
+		kvm_err("Cannot initialize protected mode without PSCI\n");
+		return false;
+	}
+
+	kvm_nvhe_sym(kvm_host_psci_version) = psci_ops.get_version();
+	kvm_nvhe_sym(kvm_host_psci_0_1_function_ids) = get_psci_0_1_function_ids();
+	return true;
+}
+
 static int init_common_resources(void)
 {
 	return kvm_set_ipa_limit();
@@ -1772,9 +1791,13 @@ static int init_hyp_mode(void)
 		}
 	}
 
-	if (is_protected_kvm_enabled())
+	if (is_protected_kvm_enabled()) {
 		init_cpu_logical_map();
 
+		if (!init_psci_relay())
+			goto out_err;
+	}
+
 	return 0;
 
 out_err:
diff --git a/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h b/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h
new file mode 100644
index 000000000000..1e6d995968a1
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/trap_handler.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Trap handler helpers.
+ *
+ * Copyright (C) 2020 - Google LLC
+ * Author: Marc Zyngier <maz@kernel.org>
+ */
+
+#ifndef __ARM64_KVM_NVHE_TRAP_HANDLER_H__
+#define __ARM64_KVM_NVHE_TRAP_HANDLER_H__
+
+#include <asm/kvm_host.h>
+
+#define cpu_reg(ctxt, r)	(ctxt)->regs.regs[r]
+#define DECLARE_REG(type, name, ctxt, reg)	\
+				type name = (type)cpu_reg(ctxt, (reg))
+
+#endif /* __ARM64_KVM_NVHE_TRAP_HANDLER_H__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index cf11f8182756..1f1e351c5fe2 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -7,7 +7,7 @@ asflags-y := -D__KVM_NVHE_HYPERVISOR__
 ccflags-y := -D__KVM_NVHE_HYPERVISOR__
 
 obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
-	 hyp-main.o hyp-smp.o
+	 hyp-main.o hyp-smp.o psci-relay.o
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o ../exception.o
 
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index f25680ede080..bde658d51404 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -12,9 +12,7 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
-#define cpu_reg(ctxt, r)	(ctxt)->regs.regs[r]
-#define DECLARE_REG(type, name, ctxt, reg)	\
-				type name = (type)cpu_reg(ctxt, (reg))
+#include <nvhe/trap_handler.h>
 
 DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
 
@@ -166,7 +164,11 @@ static void skip_host_instruction(void)
 
 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
 {
-	default_host_smc_handler(host_ctxt);
+	bool handled;
+
+	handled = kvm_host_psci_handler(host_ctxt);
+	if (!handled)
+		default_host_smc_handler(host_ctxt);
 
 	/*
 	 * Unlike HVC, the return address of an SMC is the instruction's PC.
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
new file mode 100644
index 000000000000..61375d4571c2
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 - Google LLC
+ * Author: David Brazdil <dbrazdil@google.com>
+ */
+
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+#include <kvm/arm_hypercalls.h>
+#include <linux/arm-smccc.h>
+#include <linux/psci.h>
+#include <kvm/arm_psci.h>
+#include <uapi/linux/psci.h>
+
+#include <nvhe/trap_handler.h>
+
+/* Config options set by the host. */
+__ro_after_init u32 kvm_host_psci_version;
+__ro_after_init struct psci_0_1_function_ids kvm_host_psci_0_1_function_ids;
+
+static u64 get_psci_func_id(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(u64, func_id, host_ctxt, 0);
+
+	return func_id;
+}
+
+static bool is_psci_0_1_call(u64 func_id)
+{
+	return (func_id == kvm_host_psci_0_1_function_ids.cpu_suspend) ||
+	       (func_id == kvm_host_psci_0_1_function_ids.cpu_on) ||
+	       (func_id == kvm_host_psci_0_1_function_ids.cpu_off) ||
+	       (func_id == kvm_host_psci_0_1_function_ids.migrate);
+}
+
+static bool is_psci_0_2_call(u64 func_id)
+{
+	/* SMCCC reserves IDs 0x00-1F with the given 32/64-bit base for PSCI. */
+	return (PSCI_0_2_FN(0) <= func_id && func_id <= PSCI_0_2_FN(31)) ||
+	       (PSCI_0_2_FN64(0) <= func_id && func_id <= PSCI_0_2_FN64(31));
+}
+
+static bool is_psci_call(u64 func_id)
+{
+	switch (kvm_host_psci_version) {
+	case PSCI_VERSION(0, 1):
+		return is_psci_0_1_call(func_id);
+	default:
+		return is_psci_0_2_call(func_id);
+	}
+}
+
+static unsigned long psci_0_1_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
+{
+	return PSCI_RET_NOT_SUPPORTED;
+}
+
+static unsigned long psci_0_2_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
+{
+	switch (func_id) {
+	default:
+		return PSCI_RET_NOT_SUPPORTED;
+	}
+}
+
+static unsigned long psci_1_0_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
+{
+	switch (func_id) {
+	default:
+		return psci_0_2_handler(func_id, host_ctxt);
+	}
+}
+
+bool kvm_host_psci_handler(struct kvm_cpu_context *host_ctxt)
+{
+	u64 func_id = get_psci_func_id(host_ctxt);
+	unsigned long ret;
+
+	if (!is_psci_call(func_id))
+		return false;
+
+	switch (kvm_host_psci_version) {
+	case PSCI_VERSION(0, 1):
+		ret = psci_0_1_handler(func_id, host_ctxt);
+		break;
+	case PSCI_VERSION(0, 2):
+		ret = psci_0_2_handler(func_id, host_ctxt);
+		break;
+	default:
+		ret = psci_1_0_handler(func_id, host_ctxt);
+		break;
+	}
+
+	cpu_reg(host_ctxt, 0) = ret;
+	cpu_reg(host_ctxt, 1) = 0;
+	cpu_reg(host_ctxt, 2) = 0;
+	cpu_reg(host_ctxt, 3) = 0;
+	return true;
+}
-- 
2.29.2.454.gaff20da3a2-goog


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  parent reply	other threads:[~2020-12-02 18:46 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 ` [PATCH v4 10/26] kvm: arm64: Move hyp-init params to a per-CPU struct David Brazdil
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 ` David Brazdil [this message]
2020-12-03 10:55   ` [PATCH v4 16/26] kvm: arm64: Bootstrap PSCI " 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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