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From: Andrew Scull <ascull@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
	maz@kernel.org, Sudeep Holla <sudeep.holla@arm.com>,
	catalin.marinas@arm.com, will@kernel.org
Subject: [PATCH v2 06/20] KVM: arm64: nVHE: Use separate vector for the host
Date: Thu, 20 Aug 2020 11:34:32 +0100	[thread overview]
Message-ID: <20200820103446.959000-7-ascull@google.com> (raw)
In-Reply-To: <20200820103446.959000-1-ascull@google.com>

The host is treated differently from the guests when an exception is
taken so introduce a separate vector that is specialized for the host.
This also allows the nVHE specific code to move out of hyp-entry.S and
into nvhe/host.S.

The host is only expected to make HVC calls and anything else is
considered invalid and results in a panic.

Hyp initialization is now passed the vector that is used for the host
and it is swapped for the guest vector during the context switch.

Signed-off-by: Andrew Scull <ascull@google.com>
---
 arch/arm64/include/asm/kvm_asm.h |   2 +
 arch/arm64/kernel/image-vars.h   |   1 +
 arch/arm64/kvm/arm.c             |  11 +++-
 arch/arm64/kvm/hyp/hyp-entry.S   |  65 -------------------
 arch/arm64/kvm/hyp/nvhe/Makefile |   2 +-
 arch/arm64/kvm/hyp/nvhe/host.S   | 104 +++++++++++++++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/switch.c |   3 +
 7 files changed, 121 insertions(+), 67 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/nvhe/host.S

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 413911d6446a..81f29a2c361a 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -98,10 +98,12 @@ struct kvm_vcpu;
 struct kvm_s2_mmu;
 
 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
+DECLARE_KVM_NVHE_SYM(__kvm_hyp_host_vector);
 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 
 #ifndef __KVM_NVHE_HYPERVISOR__
 #define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
+#define __kvm_hyp_host_vector	CHOOSE_NVHE_SYM(__kvm_hyp_host_vector)
 #define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)
 #endif
 
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 9e897c500237..7e93b0c426d4 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -71,6 +71,7 @@ KVM_NVHE_ALIAS(kvm_update_va_mask);
 /* Global kernel state accessed by nVHE hyp code. */
 KVM_NVHE_ALIAS(arm64_ssbd_callback_required);
 KVM_NVHE_ALIAS(kvm_host_data);
+KVM_NVHE_ALIAS(kvm_hyp_vector);
 KVM_NVHE_ALIAS(kvm_vgic_global_state);
 
 /* Kernel constant needed to compute idmap addresses. */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index d779814f0da6..c6f76fdabecb 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1277,7 +1277,7 @@ static void cpu_init_hyp_mode(void)
 
 	pgd_ptr = kvm_mmu_get_httbr();
 	hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
-	vector_ptr = __this_cpu_read(kvm_hyp_vector);
+	vector_ptr = (unsigned long)kern_hyp_va(kvm_ksym_ref(__kvm_hyp_host_vector));
 
 	/*
 	 * Call initialization code, and switch to the full blown HYP code.
@@ -1542,6 +1542,7 @@ static int init_hyp_mode(void)
 
 	for_each_possible_cpu(cpu) {
 		struct kvm_host_data *cpu_data;
+		unsigned long *vector;
 
 		cpu_data = per_cpu_ptr(&kvm_host_data, cpu);
 		err = create_hyp_mappings(cpu_data, cpu_data + 1, PAGE_HYP);
@@ -1550,6 +1551,14 @@ static int init_hyp_mode(void)
 			kvm_err("Cannot map host CPU state: %d\n", err);
 			goto out_err;
 		}
+
+		vector = per_cpu_ptr(&kvm_hyp_vector, cpu);
+		err = create_hyp_mappings(vector, vector + 1, PAGE_HYP);
+
+		if (err) {
+			kvm_err("Cannot map hyp guest vector address\n");
+			goto out_err;
+		}
 	}
 
 	err = hyp_map_aux_data();
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index b0923e9f9291..6e14873680a8 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -12,25 +12,10 @@
 #include <asm/cpufeature.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
-#include <asm/kvm_mmu.h>
 #include <asm/mmu.h>
 
 	.text
 
-.macro do_el2_call
-	/*
-	 * Shuffle the parameters before calling the function
-	 * pointed to in x0. Assumes parameters in x[1,2,3].
-	 */
-	str	lr, [sp, #-16]!
-	mov	lr, x0
-	mov	x0, x1
-	mov	x1, x2
-	mov	x2, x3
-	blr	lr
-	ldr	lr, [sp], #16
-.endm
-
 el1_sync:				// Guest trapped into EL2
 
 	mrs	x0, esr_el2
@@ -39,43 +24,6 @@ el1_sync:				// Guest trapped into EL2
 	ccmp	x0, #ESR_ELx_EC_HVC32, #4, ne
 	b.ne	el1_trap
 
-#ifdef __KVM_NVHE_HYPERVISOR__
-	mrs	x1, vttbr_el2		// If vttbr is valid, the guest
-	cbnz	x1, el1_hvc_guest	// called HVC
-
-	/* Here, we're pretty sure the host called HVC. */
-	ldp	x0, x1, [sp], #16
-
-	/* Check for a stub HVC call */
-	cmp	x0, #HVC_STUB_HCALL_NR
-	b.hs	1f
-
-	/*
-	 * Compute the idmap address of __kvm_handle_stub_hvc and
-	 * jump there. Since we use kimage_voffset, do not use the
-	 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead
-	 * (by loading it from the constant pool).
-	 *
-	 * Preserve x0-x4, which may contain stub parameters.
-	 */
-	ldr	x5, =__kvm_handle_stub_hvc
-	ldr_l	x6, kimage_voffset
-
-	/* x5 = __pa(x5) */
-	sub	x5, x5, x6
-	br	x5
-
-1:
-	/*
-	 * Perform the EL2 call
-	 */
-	kern_hyp_va	x0
-	do_el2_call
-
-	eret
-	sb
-#endif /* __KVM_NVHE_HYPERVISOR__ */
-
 el1_hvc_guest:
 	/*
 	 * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1.
@@ -181,18 +129,6 @@ el2_error:
 	eret
 	sb
 
-#ifdef __KVM_NVHE_HYPERVISOR__
-SYM_FUNC_START(__hyp_do_panic)
-	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
-		      PSR_MODE_EL1h)
-	msr	spsr_el2, lr
-	ldr	lr, =panic
-	msr	elr_el2, lr
-	eret
-	sb
-SYM_FUNC_END(__hyp_do_panic)
-#endif
-
 .macro invalid_vector	label, target = hyp_panic
 	.align	2
 SYM_CODE_START(\label)
@@ -205,7 +141,6 @@ SYM_CODE_END(\label)
 	invalid_vector	el2t_irq_invalid
 	invalid_vector	el2t_fiq_invalid
 	invalid_vector	el2t_error_invalid
-	invalid_vector	el2h_sync_invalid
 	invalid_vector	el2h_irq_invalid
 	invalid_vector	el2h_fiq_invalid
 	invalid_vector	el1_fiq_invalid
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index aef76487edc2..ddf98eb07b9d 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -6,7 +6,7 @@
 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
+obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o
 
diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
new file mode 100644
index 000000000000..9c96b9a3b71d
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 - Google Inc
+ * Author: Andrew Scull <ascull@google.com>
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_mmu.h>
+
+	.text
+
+SYM_FUNC_START(__hyp_do_panic)
+	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
+		      PSR_MODE_EL1h)
+	msr	spsr_el2, lr
+	ldr	lr, =panic
+	msr	elr_el2, lr
+	eret
+	sb
+SYM_FUNC_END(__hyp_do_panic)
+
+.macro valid_host_el1_sync_vect
+	.align 7
+	esb
+	stp	x0, x1, [sp, #-16]!
+
+	mrs	x0, esr_el2
+	lsr	x0, x0, #ESR_ELx_EC_SHIFT
+	cmp	x0, #ESR_ELx_EC_HVC64
+	b.ne	hyp_panic
+
+	ldp	x0, x1, [sp], #16
+
+	/* Check for a stub HVC call */
+	cmp	x0, #HVC_STUB_HCALL_NR
+	b.hs	1f
+
+	/*
+	 * Compute the idmap address of __kvm_handle_stub_hvc and
+	 * jump there. Since we use kimage_voffset, do not use the
+	 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead
+	 * (by loading it from the constant pool).
+	 *
+	 * Preserve x0-x4, which may contain stub parameters.
+	 */
+	ldr	x5, =__kvm_handle_stub_hvc
+	ldr_l	x6, kimage_voffset
+
+	/* x5 = __pa(x5) */
+	sub	x5, x5, x6
+	br	x5
+
+1:
+	/*
+	 * Shuffle the parameters before calling the function
+	 * pointed to in x0. Assumes parameters in x[1,2,3].
+	 */
+	kern_hyp_va	x0
+	str	lr, [sp, #-16]!
+	mov	lr, x0
+	mov	x0, x1
+	mov	x1, x2
+	mov	x2, x3
+	blr	lr
+	ldr	lr, [sp], #16
+
+	eret
+	sb
+.endm
+
+.macro invalid_host_vect
+	.align 7
+	b	hyp_panic
+.endm
+
+/*
+ * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vector because the
+ * host already knows the address of hyp by virtue of loading it there.
+ */
+	.align 11
+SYM_CODE_START(__kvm_hyp_host_vector)
+	invalid_host_vect			// Synchronous EL2t
+	invalid_host_vect			// IRQ EL2t
+	invalid_host_vect			// FIQ EL2t
+	invalid_host_vect			// Error EL2t
+
+	invalid_host_vect			// Synchronous EL2h
+	invalid_host_vect			// IRQ EL2h
+	invalid_host_vect			// FIQ EL2h
+	invalid_host_vect			// Error EL2h
+
+	valid_host_el1_sync_vect		// Synchronous 64-bit EL1
+	invalid_host_vect			// IRQ 64-bit EL1
+	invalid_host_vect			// FIQ 64-bit EL1
+	invalid_host_vect			// Error 64-bit EL1
+
+	invalid_host_vect			// Synchronous 32-bit EL1
+	invalid_host_vect			// IRQ 32-bit EL1
+	invalid_host_vect			// FIQ 32-bit EL1
+	invalid_host_vect			// Error 32-bit EL1
+SYM_CODE_END(__kvm_hyp_host_vector)
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index f969a6dc4741..05bb0b472091 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -42,6 +42,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 	}
 
 	write_sysreg(val, cptr_el2);
+	write_sysreg(__hyp_this_cpu_read(kvm_hyp_vector), vbar_el2);
 
 	if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
 		struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
@@ -60,6 +61,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 
 static void __deactivate_traps(struct kvm_vcpu *vcpu)
 {
+	extern char __kvm_hyp_host_vector[];
 	u64 mdcr_el2;
 
 	___deactivate_traps(vcpu);
@@ -91,6 +93,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 	write_sysreg(mdcr_el2, mdcr_el2);
 	write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
 	write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
+	write_sysreg(__kvm_hyp_host_vector, vbar_el2);
 }
 
 static void __load_host_stage2(void)
-- 
2.28.0.220.ged08abb693-goog

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WARNING: multiple messages have this Message-ID (diff)
From: Andrew Scull <ascull@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
	suzuki.poulose@arm.com, maz@kernel.org,
	Sudeep Holla <sudeep.holla@arm.com>,
	james.morse@arm.com, Andrew Scull <ascull@google.com>,
	catalin.marinas@arm.com, will@kernel.org,
	julien.thierry.kdev@gmail.com
Subject: [PATCH v2 06/20] KVM: arm64: nVHE: Use separate vector for the host
Date: Thu, 20 Aug 2020 11:34:32 +0100	[thread overview]
Message-ID: <20200820103446.959000-7-ascull@google.com> (raw)
In-Reply-To: <20200820103446.959000-1-ascull@google.com>

The host is treated differently from the guests when an exception is
taken so introduce a separate vector that is specialized for the host.
This also allows the nVHE specific code to move out of hyp-entry.S and
into nvhe/host.S.

The host is only expected to make HVC calls and anything else is
considered invalid and results in a panic.

Hyp initialization is now passed the vector that is used for the host
and it is swapped for the guest vector during the context switch.

Signed-off-by: Andrew Scull <ascull@google.com>
---
 arch/arm64/include/asm/kvm_asm.h |   2 +
 arch/arm64/kernel/image-vars.h   |   1 +
 arch/arm64/kvm/arm.c             |  11 +++-
 arch/arm64/kvm/hyp/hyp-entry.S   |  65 -------------------
 arch/arm64/kvm/hyp/nvhe/Makefile |   2 +-
 arch/arm64/kvm/hyp/nvhe/host.S   | 104 +++++++++++++++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/switch.c |   3 +
 7 files changed, 121 insertions(+), 67 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/nvhe/host.S

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 413911d6446a..81f29a2c361a 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -98,10 +98,12 @@ struct kvm_vcpu;
 struct kvm_s2_mmu;
 
 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
+DECLARE_KVM_NVHE_SYM(__kvm_hyp_host_vector);
 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 
 #ifndef __KVM_NVHE_HYPERVISOR__
 #define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
+#define __kvm_hyp_host_vector	CHOOSE_NVHE_SYM(__kvm_hyp_host_vector)
 #define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)
 #endif
 
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 9e897c500237..7e93b0c426d4 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -71,6 +71,7 @@ KVM_NVHE_ALIAS(kvm_update_va_mask);
 /* Global kernel state accessed by nVHE hyp code. */
 KVM_NVHE_ALIAS(arm64_ssbd_callback_required);
 KVM_NVHE_ALIAS(kvm_host_data);
+KVM_NVHE_ALIAS(kvm_hyp_vector);
 KVM_NVHE_ALIAS(kvm_vgic_global_state);
 
 /* Kernel constant needed to compute idmap addresses. */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index d779814f0da6..c6f76fdabecb 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1277,7 +1277,7 @@ static void cpu_init_hyp_mode(void)
 
 	pgd_ptr = kvm_mmu_get_httbr();
 	hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
-	vector_ptr = __this_cpu_read(kvm_hyp_vector);
+	vector_ptr = (unsigned long)kern_hyp_va(kvm_ksym_ref(__kvm_hyp_host_vector));
 
 	/*
 	 * Call initialization code, and switch to the full blown HYP code.
@@ -1542,6 +1542,7 @@ static int init_hyp_mode(void)
 
 	for_each_possible_cpu(cpu) {
 		struct kvm_host_data *cpu_data;
+		unsigned long *vector;
 
 		cpu_data = per_cpu_ptr(&kvm_host_data, cpu);
 		err = create_hyp_mappings(cpu_data, cpu_data + 1, PAGE_HYP);
@@ -1550,6 +1551,14 @@ static int init_hyp_mode(void)
 			kvm_err("Cannot map host CPU state: %d\n", err);
 			goto out_err;
 		}
+
+		vector = per_cpu_ptr(&kvm_hyp_vector, cpu);
+		err = create_hyp_mappings(vector, vector + 1, PAGE_HYP);
+
+		if (err) {
+			kvm_err("Cannot map hyp guest vector address\n");
+			goto out_err;
+		}
 	}
 
 	err = hyp_map_aux_data();
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index b0923e9f9291..6e14873680a8 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -12,25 +12,10 @@
 #include <asm/cpufeature.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
-#include <asm/kvm_mmu.h>
 #include <asm/mmu.h>
 
 	.text
 
-.macro do_el2_call
-	/*
-	 * Shuffle the parameters before calling the function
-	 * pointed to in x0. Assumes parameters in x[1,2,3].
-	 */
-	str	lr, [sp, #-16]!
-	mov	lr, x0
-	mov	x0, x1
-	mov	x1, x2
-	mov	x2, x3
-	blr	lr
-	ldr	lr, [sp], #16
-.endm
-
 el1_sync:				// Guest trapped into EL2
 
 	mrs	x0, esr_el2
@@ -39,43 +24,6 @@ el1_sync:				// Guest trapped into EL2
 	ccmp	x0, #ESR_ELx_EC_HVC32, #4, ne
 	b.ne	el1_trap
 
-#ifdef __KVM_NVHE_HYPERVISOR__
-	mrs	x1, vttbr_el2		// If vttbr is valid, the guest
-	cbnz	x1, el1_hvc_guest	// called HVC
-
-	/* Here, we're pretty sure the host called HVC. */
-	ldp	x0, x1, [sp], #16
-
-	/* Check for a stub HVC call */
-	cmp	x0, #HVC_STUB_HCALL_NR
-	b.hs	1f
-
-	/*
-	 * Compute the idmap address of __kvm_handle_stub_hvc and
-	 * jump there. Since we use kimage_voffset, do not use the
-	 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead
-	 * (by loading it from the constant pool).
-	 *
-	 * Preserve x0-x4, which may contain stub parameters.
-	 */
-	ldr	x5, =__kvm_handle_stub_hvc
-	ldr_l	x6, kimage_voffset
-
-	/* x5 = __pa(x5) */
-	sub	x5, x5, x6
-	br	x5
-
-1:
-	/*
-	 * Perform the EL2 call
-	 */
-	kern_hyp_va	x0
-	do_el2_call
-
-	eret
-	sb
-#endif /* __KVM_NVHE_HYPERVISOR__ */
-
 el1_hvc_guest:
 	/*
 	 * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1.
@@ -181,18 +129,6 @@ el2_error:
 	eret
 	sb
 
-#ifdef __KVM_NVHE_HYPERVISOR__
-SYM_FUNC_START(__hyp_do_panic)
-	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
-		      PSR_MODE_EL1h)
-	msr	spsr_el2, lr
-	ldr	lr, =panic
-	msr	elr_el2, lr
-	eret
-	sb
-SYM_FUNC_END(__hyp_do_panic)
-#endif
-
 .macro invalid_vector	label, target = hyp_panic
 	.align	2
 SYM_CODE_START(\label)
@@ -205,7 +141,6 @@ SYM_CODE_END(\label)
 	invalid_vector	el2t_irq_invalid
 	invalid_vector	el2t_fiq_invalid
 	invalid_vector	el2t_error_invalid
-	invalid_vector	el2h_sync_invalid
 	invalid_vector	el2h_irq_invalid
 	invalid_vector	el2h_fiq_invalid
 	invalid_vector	el1_fiq_invalid
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index aef76487edc2..ddf98eb07b9d 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -6,7 +6,7 @@
 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
+obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o
 
diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
new file mode 100644
index 000000000000..9c96b9a3b71d
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 - Google Inc
+ * Author: Andrew Scull <ascull@google.com>
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_mmu.h>
+
+	.text
+
+SYM_FUNC_START(__hyp_do_panic)
+	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
+		      PSR_MODE_EL1h)
+	msr	spsr_el2, lr
+	ldr	lr, =panic
+	msr	elr_el2, lr
+	eret
+	sb
+SYM_FUNC_END(__hyp_do_panic)
+
+.macro valid_host_el1_sync_vect
+	.align 7
+	esb
+	stp	x0, x1, [sp, #-16]!
+
+	mrs	x0, esr_el2
+	lsr	x0, x0, #ESR_ELx_EC_SHIFT
+	cmp	x0, #ESR_ELx_EC_HVC64
+	b.ne	hyp_panic
+
+	ldp	x0, x1, [sp], #16
+
+	/* Check for a stub HVC call */
+	cmp	x0, #HVC_STUB_HCALL_NR
+	b.hs	1f
+
+	/*
+	 * Compute the idmap address of __kvm_handle_stub_hvc and
+	 * jump there. Since we use kimage_voffset, do not use the
+	 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead
+	 * (by loading it from the constant pool).
+	 *
+	 * Preserve x0-x4, which may contain stub parameters.
+	 */
+	ldr	x5, =__kvm_handle_stub_hvc
+	ldr_l	x6, kimage_voffset
+
+	/* x5 = __pa(x5) */
+	sub	x5, x5, x6
+	br	x5
+
+1:
+	/*
+	 * Shuffle the parameters before calling the function
+	 * pointed to in x0. Assumes parameters in x[1,2,3].
+	 */
+	kern_hyp_va	x0
+	str	lr, [sp, #-16]!
+	mov	lr, x0
+	mov	x0, x1
+	mov	x1, x2
+	mov	x2, x3
+	blr	lr
+	ldr	lr, [sp], #16
+
+	eret
+	sb
+.endm
+
+.macro invalid_host_vect
+	.align 7
+	b	hyp_panic
+.endm
+
+/*
+ * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vector because the
+ * host already knows the address of hyp by virtue of loading it there.
+ */
+	.align 11
+SYM_CODE_START(__kvm_hyp_host_vector)
+	invalid_host_vect			// Synchronous EL2t
+	invalid_host_vect			// IRQ EL2t
+	invalid_host_vect			// FIQ EL2t
+	invalid_host_vect			// Error EL2t
+
+	invalid_host_vect			// Synchronous EL2h
+	invalid_host_vect			// IRQ EL2h
+	invalid_host_vect			// FIQ EL2h
+	invalid_host_vect			// Error EL2h
+
+	valid_host_el1_sync_vect		// Synchronous 64-bit EL1
+	invalid_host_vect			// IRQ 64-bit EL1
+	invalid_host_vect			// FIQ 64-bit EL1
+	invalid_host_vect			// Error 64-bit EL1
+
+	invalid_host_vect			// Synchronous 32-bit EL1
+	invalid_host_vect			// IRQ 32-bit EL1
+	invalid_host_vect			// FIQ 32-bit EL1
+	invalid_host_vect			// Error 32-bit EL1
+SYM_CODE_END(__kvm_hyp_host_vector)
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index f969a6dc4741..05bb0b472091 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -42,6 +42,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 	}
 
 	write_sysreg(val, cptr_el2);
+	write_sysreg(__hyp_this_cpu_read(kvm_hyp_vector), vbar_el2);
 
 	if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
 		struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
@@ -60,6 +61,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 
 static void __deactivate_traps(struct kvm_vcpu *vcpu)
 {
+	extern char __kvm_hyp_host_vector[];
 	u64 mdcr_el2;
 
 	___deactivate_traps(vcpu);
@@ -91,6 +93,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 	write_sysreg(mdcr_el2, mdcr_el2);
 	write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
 	write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
+	write_sysreg(__kvm_hyp_host_vector, vbar_el2);
 }
 
 static void __load_host_stage2(void)
-- 
2.28.0.220.ged08abb693-goog


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  parent reply	other threads:[~2020-08-20 10:35 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-20 10:34 [PATCH v2 00/20] Introduce separate nVHE hyp context Andrew Scull
2020-08-20 10:34 ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 01/20] KVM: arm64: Remove __activate_vm wrapper Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 02/20] KVM: arm64: Remove hyp_panic arguments Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 03/20] KVM: arm64: Remove kvm_host_data_t typedef Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 04/20] KVM: arm64: Restrict symbol aliasing to outside nVHE Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 05/20] KVM: arm64: Save chosen hyp vector to a percpu variable Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` Andrew Scull [this message]
2020-08-20 10:34   ` [PATCH v2 06/20] KVM: arm64: nVHE: Use separate vector for the host Andrew Scull
2020-08-20 10:34 ` [PATCH v2 07/20] KVM: arm64: nVHE: Don't consume host SErrors with ESB Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 08/20] KVM: arm64: Preserve host DISR_EL1 Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 09/20] KVM: arm64: Introduce hyp context Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 10/20] KVM: arm64: Update context references from host to hyp Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 11/20] KVM: arm64: Restore hyp when panicking in guest context Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 12/20] KVM: arm64: Share context save and restore macros Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 13/20] KVM: arm64: nVHE: Switch to hyp context for EL2 Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 14/20] KVM: arm64: nVHE: Handle hyp panics Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 15/20] smccc: Cast arguments to unsigned long Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 16/20] KVM: arm64: nVHE: Pass pointers consistently to hyp-init Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 17/20] KVM: arm64: nVHE: Migrate hyp interface to SMCCC Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 18/20] KVM: arm64: nVHE: Migrate hyp-init " Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 19/20] KVM: arm64: nVHE: Fix pointers during SMCCC convertion Andrew Scull
2020-08-20 10:34   ` Andrew Scull
2020-08-20 10:34 ` [PATCH v2 20/20] KVM: arm64: nVHE: Handle stub HVCs in the host loop Andrew Scull
2020-08-20 10:34   ` Andrew Scull

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