From b1da49088ac68a21c613efd734dada8272ec0b00 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Sat, 28 May 2022 12:38:19 +0100
Subject: KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag set

The three debug flags (which deal with the debug registers, SPE and
TRBE) all are input flags to the hypervisor code.

Move them into the input set and convert them to the new accessors.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c06c0477fab5..f24797c57df8 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -387,7 +387,7 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu,
 {
 	if (p->is_write) {
 		vcpu_write_sys_reg(vcpu, p->regval, r->reg);
-		vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
+		vcpu_set_flag(vcpu, DEBUG_DIRTY);
 	} else {
 		p->regval = vcpu_read_sys_reg(vcpu, r->reg);
 	}
@@ -403,8 +403,8 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu,
  * A 32 bit write to a debug register leave top bits alone
  * A 32 bit read from a debug register only returns the bottom bits
  *
- * All writes will set the KVM_ARM64_DEBUG_DIRTY flag to ensure the
- * hyp.S code switches between host and guest values in future.
+ * All writes will set the DEBUG_DIRTY flag to ensure the hyp code
+ * switches between host and guest values in future.
  */
 static void reg_to_dbg(struct kvm_vcpu *vcpu,
 		       struct sys_reg_params *p,
@@ -420,7 +420,7 @@ static void reg_to_dbg(struct kvm_vcpu *vcpu,
 	val |= (p->regval & (mask >> shift)) << shift;
 	*dbg_reg = val;
 
-	vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
+	vcpu_set_flag(vcpu, DEBUG_DIRTY);
 }
 
 static void dbg_to_reg(struct kvm_vcpu *vcpu,
-- 
cgit v1.2.3


From 30b6ab45f81334e83dcb440451b6a4c4a753a118 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Sat, 28 May 2022 12:38:24 +0100
Subject: KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flag

The aptly named boolean 'sysregs_loaded_on_cpu' tracks whether
some of the vcpu system registers are resident on the physical
CPU when running in VHE mode.

This is obviously a flag in hidding, so let's convert it to
a state flag, since this is solely a host concern (the hypervisor
itself always knows which state we're in).

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h  | 6 ++----
 arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 4 ++--
 arch/arm64/kvm/sys_regs.c          | 4 ++--
 3 files changed, 6 insertions(+), 8 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 39da28f85045..ffbeb5f5692e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -410,10 +410,6 @@ struct kvm_vcpu_arch {
 	/* Additional reset state */
 	struct vcpu_reset_state	reset_state;
 
-	/* True when deferrable sysregs are loaded on the physical CPU,
-	 * see kvm_vcpu_load_sysregs_vhe and kvm_vcpu_put_sysregs_vhe. */
-	bool sysregs_loaded_on_cpu;
-
 	/* Guest PV state */
 	struct {
 		u64 last_steal;
@@ -520,6 +516,8 @@ struct kvm_vcpu_arch {
 #define ON_UNSUPPORTED_CPU	__vcpu_single_flag(sflags, BIT(2))
 /* WFIT instruction trapped */
 #define IN_WFIT			__vcpu_single_flag(sflags, BIT(3))
+/* vcpu system registers loaded on physical CPU */
+#define SYSREGS_ON_CPU		__vcpu_single_flag(sflags, BIT(4))
 
 /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
 #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) +	\
diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
index 007a12dd4351..7b44f6b3b547 100644
--- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
@@ -79,7 +79,7 @@ void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu)
 	__sysreg_restore_user_state(guest_ctxt);
 	__sysreg_restore_el1_state(guest_ctxt);
 
-	vcpu->arch.sysregs_loaded_on_cpu = true;
+	vcpu_set_flag(vcpu, SYSREGS_ON_CPU);
 
 	activate_traps_vhe_load(vcpu);
 }
@@ -110,5 +110,5 @@ void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu)
 	/* Restore host user state */
 	__sysreg_restore_user_state(host_ctxt);
 
-	vcpu->arch.sysregs_loaded_on_cpu = false;
+	vcpu_clear_flag(vcpu, SYSREGS_ON_CPU);
 }
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index f24797c57df8..1c562bcfeccf 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -72,7 +72,7 @@ u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
 {
 	u64 val = 0x8badf00d8badf00d;
 
-	if (vcpu->arch.sysregs_loaded_on_cpu &&
+	if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) &&
 	    __vcpu_read_sys_reg_from_cpu(reg, &val))
 		return val;
 
@@ -81,7 +81,7 @@ u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
 
 void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
 {
-	if (vcpu->arch.sysregs_loaded_on_cpu &&
+	if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) &&
 	    __vcpu_write_sys_reg_to_cpu(val, reg))
 		return;
 
-- 
cgit v1.2.3


From da8d120fbafe1d3217d25ac45493538b37cff87c Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Sun, 3 Jul 2022 14:08:46 +0100
Subject: KVM: arm64: Add get_reg_by_id() as a sys_reg_desc retrieving helper

find_reg_by_id() requires a sys_reg_param as input, which most
users provide as a on-stack variable, but don't make any use of
the result.

Provide a helper that doesn't have this requirement and simplify
the callers (all but one).

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c        | 28 +++++++++++++++++-----------
 arch/arm64/kvm/sys_regs.h        |  4 ++++
 arch/arm64/kvm/vgic-sys-reg-v3.c |  8 ++------
 3 files changed, 23 insertions(+), 17 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c06c0477fab5..1f410283c592 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2650,21 +2650,29 @@ const struct sys_reg_desc *find_reg_by_id(u64 id,
 	return find_reg(params, table, num);
 }
 
+const struct sys_reg_desc *get_reg_by_id(u64 id,
+					 const struct sys_reg_desc table[],
+					 unsigned int num)
+{
+	struct sys_reg_params params;
+
+	if (!index_to_params(id, &params))
+		return NULL;
+
+	return find_reg(&params, table, num);
+}
+
 /* Decode an index value, and find the sys_reg_desc entry. */
 static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
 						    u64 id)
 {
 	const struct sys_reg_desc *r;
-	struct sys_reg_params params;
 
 	/* We only do sys_reg for now. */
 	if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
 		return NULL;
 
-	if (!index_to_params(id, &params))
-		return NULL;
-
-	r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
+	r = get_reg_by_id(id, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
 
 	/* Not saved in the sys_reg array and not otherwise accessible? */
 	if (r && !(r->reg || r->get_user))
@@ -2723,11 +2731,10 @@ static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)
 
 static int get_invariant_sys_reg(u64 id, void __user *uaddr)
 {
-	struct sys_reg_params params;
 	const struct sys_reg_desc *r;
 
-	r = find_reg_by_id(id, &params, invariant_sys_regs,
-			   ARRAY_SIZE(invariant_sys_regs));
+	r = get_reg_by_id(id, invariant_sys_regs,
+			  ARRAY_SIZE(invariant_sys_regs));
 	if (!r)
 		return -ENOENT;
 
@@ -2736,13 +2743,12 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr)
 
 static int set_invariant_sys_reg(u64 id, void __user *uaddr)
 {
-	struct sys_reg_params params;
 	const struct sys_reg_desc *r;
 	int err;
 	u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
 
-	r = find_reg_by_id(id, &params, invariant_sys_regs,
-			   ARRAY_SIZE(invariant_sys_regs));
+	r = get_reg_by_id(id, invariant_sys_regs,
+			  ARRAY_SIZE(invariant_sys_regs));
 	if (!r)
 		return -ENOENT;
 
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index aee8ea054f0d..ce30ed9566ae 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -195,6 +195,10 @@ const struct sys_reg_desc *find_reg_by_id(u64 id,
 					  const struct sys_reg_desc table[],
 					  unsigned int num);
 
+const struct sys_reg_desc *get_reg_by_id(u64 id,
+					 const struct sys_reg_desc table[],
+					 unsigned int num);
+
 #define AA32(_x)	.aarch32_map = AA32_##_x
 #define Op0(_x) 	.Op0 = _x
 #define Op1(_x) 	.Op1 = _x
diff --git a/arch/arm64/kvm/vgic-sys-reg-v3.c b/arch/arm64/kvm/vgic-sys-reg-v3.c
index 07d5271e9f05..644acda33c7c 100644
--- a/arch/arm64/kvm/vgic-sys-reg-v3.c
+++ b/arch/arm64/kvm/vgic-sys-reg-v3.c
@@ -263,14 +263,10 @@ static const struct sys_reg_desc gic_v3_icc_reg_descs[] = {
 int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
 				u64 *reg)
 {
-	struct sys_reg_params params;
 	u64 sysreg = (id & KVM_DEV_ARM_VGIC_SYSREG_MASK) | KVM_REG_SIZE_U64;
 
-	params.regval = *reg;
-	params.is_write = is_write;
-
-	if (find_reg_by_id(sysreg, &params, gic_v3_icc_reg_descs,
-			      ARRAY_SIZE(gic_v3_icc_reg_descs)))
+	if (get_reg_by_id(sysreg, gic_v3_icc_reg_descs,
+			  ARRAY_SIZE(gic_v3_icc_reg_descs)))
 		return 0;
 
 	return -ENXIO;
-- 
cgit v1.2.3


From 1deeffb559663dc44e4b8a61fe7e271fe3b4b836 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Sun, 3 Jul 2022 15:11:50 +0100
Subject: KVM: arm64: Reorder handling of invariant sysregs from userspace

In order to allow some further refactor of the sysreg helpers,
move the handling of invariant sysreg to occur before we handle
all the other ones.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1f410283c592..9291cb94c2e4 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2849,6 +2849,7 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 {
 	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	int err;
 
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_get(reg->id, uaddr);
@@ -2856,12 +2857,14 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
 		return -ENOENT;
 
+	err = get_invariant_sys_reg(reg->id, uaddr);
+	if (err != -ENOENT)
+		return err;
+
 	r = index_to_sys_reg_desc(vcpu, reg->id);
-	if (!r)
-		return get_invariant_sys_reg(reg->id, uaddr);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden(vcpu, r))
+	if (!r || sysreg_hidden(vcpu, r))
 		return -ENOENT;
 
 	if (r->get_user)
@@ -2874,6 +2877,7 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 {
 	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	int err;
 
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_set(reg->id, uaddr);
@@ -2881,12 +2885,14 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
 		return -ENOENT;
 
+	err = set_invariant_sys_reg(reg->id, uaddr);
+	if (err != -ENOENT)
+		return err;
+
 	r = index_to_sys_reg_desc(vcpu, reg->id);
-	if (!r)
-		return set_invariant_sys_reg(reg->id, uaddr);
 
 	/* Check for regs disabled by runtime config */
-	if (sysreg_hidden(vcpu, r))
+	if (!r || sysreg_hidden(vcpu, r))
 		return -ENOENT;
 
 	if (r->set_user)
-- 
cgit v1.2.3


From ba23aec9f4f27c00ac7a504aae60cae8a4087a19 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Sun, 3 Jul 2022 16:06:51 +0100
Subject: KVM: arm64: Introduce generic get_user/set_user helpers for system
 registers

The userspace access to the system registers is done using helpers
that hardcode the table that is looked up. extract some generic
helpers from this, moving the handling of hidden sysregs into
the core code.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 60 ++++++++++++++++++++++++++++++-----------------
 arch/arm64/kvm/sys_regs.h |  6 +++++
 2 files changed, 44 insertions(+), 22 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 9291cb94c2e4..0fbdb21a3600 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2663,8 +2663,10 @@ const struct sys_reg_desc *get_reg_by_id(u64 id,
 }
 
 /* Decode an index value, and find the sys_reg_desc entry. */
-static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
-						    u64 id)
+static const struct sys_reg_desc *
+id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id,
+		   const struct sys_reg_desc table[], unsigned int num)
+
 {
 	const struct sys_reg_desc *r;
 
@@ -2672,10 +2674,10 @@ static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
 	if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
 		return NULL;
 
-	r = get_reg_by_id(id, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
+	r = get_reg_by_id(id, table, num);
 
 	/* Not saved in the sys_reg array and not otherwise accessible? */
-	if (r && !(r->reg || r->get_user))
+	if (r && (!(r->reg || r->get_user) || sysreg_hidden(vcpu, r)))
 		r = NULL;
 
 	return r;
@@ -2845,9 +2847,24 @@ static int demux_c15_set(u64 id, void __user *uaddr)
 	}
 }
 
-int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
+			 const struct sys_reg_desc table[], unsigned int num)
 {
+	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
 	const struct sys_reg_desc *r;
+
+	r = id_to_sys_reg_desc(vcpu, reg->id, table, num);
+	if (!r)
+		return -ENOENT;
+
+	if (r->get_user)
+		return (r->get_user)(vcpu, r, reg, uaddr);
+
+	return reg_to_user(uaddr, &__vcpu_sys_reg(vcpu, r->reg), reg->id);
+}
+
+int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
 	int err;
 
@@ -2861,21 +2878,28 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (err != -ENOENT)
 		return err;
 
-	r = index_to_sys_reg_desc(vcpu, reg->id);
+	return kvm_sys_reg_get_user(vcpu, reg,
+				    sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
+}
 
-	/* Check for regs disabled by runtime config */
-	if (!r || sysreg_hidden(vcpu, r))
+int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
+			 const struct sys_reg_desc table[], unsigned int num)
+{
+	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	const struct sys_reg_desc *r;
+
+	r = id_to_sys_reg_desc(vcpu, reg->id, table, num);
+	if (!r)
 		return -ENOENT;
 
-	if (r->get_user)
-		return (r->get_user)(vcpu, r, reg, uaddr);
+	if (r->set_user)
+		return (r->set_user)(vcpu, r, reg, uaddr);
 
-	return reg_to_user(uaddr, &__vcpu_sys_reg(vcpu, r->reg), reg->id);
+	return reg_from_user(&__vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
 }
 
 int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 {
-	const struct sys_reg_desc *r;
 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
 	int err;
 
@@ -2889,16 +2913,8 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if (err != -ENOENT)
 		return err;
 
-	r = index_to_sys_reg_desc(vcpu, reg->id);
-
-	/* Check for regs disabled by runtime config */
-	if (!r || sysreg_hidden(vcpu, r))
-		return -ENOENT;
-
-	if (r->set_user)
-		return (r->set_user)(vcpu, r, reg, uaddr);
-
-	return reg_from_user(&__vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
+	return kvm_sys_reg_set_user(vcpu, reg,
+				    sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
 }
 
 static unsigned int num_demux_regs(void)
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index ce30ed9566ae..4fb6d59e7874 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -199,6 +199,12 @@ const struct sys_reg_desc *get_reg_by_id(u64 id,
 					 const struct sys_reg_desc table[],
 					 unsigned int num);
 
+int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
+			 const struct sys_reg_desc table[], unsigned int num);
+
+int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
+			 const struct sys_reg_desc table[], unsigned int num);
+
 #define AA32(_x)	.aarch32_map = AA32_##_x
 #define Op0(_x) 	.Op0 = _x
 #define Op1(_x) 	.Op1 = _x
-- 
cgit v1.2.3


From e48407ff9796529a1e5048b9e4d6ea8a0334468e Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 4 Jul 2022 17:01:50 +0100
Subject: KVM: arm64: Rely on index_to_param() for size checks on userspace
 access

index_to_param() already checks that we use 64bit accesses for all
registers accessed from userspace.

However, we have extra checks in other places (such as index_to_params),
which is pretty confusing. Get rid off these redundant checks.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 6 ------
 1 file changed, 6 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0fbdb21a3600..5dbe0f4b8167 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2871,9 +2871,6 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_get(reg->id, uaddr);
 
-	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
-		return -ENOENT;
-
 	err = get_invariant_sys_reg(reg->id, uaddr);
 	if (err != -ENOENT)
 		return err;
@@ -2906,9 +2903,6 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
 		return demux_c15_set(reg->id, uaddr);
 
-	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
-		return -ENOENT;
-
 	err = set_invariant_sys_reg(reg->id, uaddr);
 	if (err != -ENOENT)
 		return err;
-- 
cgit v1.2.3


From 978ceeb3e40a59973ff1d1c3d23484f71f141819 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 4 Jul 2022 17:27:00 +0100
Subject: KVM: arm64: Consolidate sysreg userspace accesses

Until now, the .set_user and .get_user callbacks have to implement
(directly or not) the userspace memory accesses. Although this gives
us maximem flexibility, this is also a maintenance burden, making it
hard to audit, and I'd feel much better if it was all located in
a single place.

So let's do just that, simplifying most of the function signatures
in the process (the callbacks are now only concerned with the
data itself, and not with userspace).

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 160 +++++++++++++++++-----------------------------
 arch/arm64/kvm/sys_regs.h |   4 +-
 2 files changed, 61 insertions(+), 103 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 5dbe0f4b8167..526798524697 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -321,16 +321,8 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
 }
 
 static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			 const struct kvm_one_reg *reg, void __user *uaddr)
+			 u64 val)
 {
-	u64 id = sys_reg_to_index(rd);
-	u64 val;
-	int err;
-
-	err = reg_from_user(&val, uaddr, id);
-	if (err)
-		return err;
-
 	/*
 	 * The only modifiable bit is the OSLK bit. Refuse the write if
 	 * userspace attempts to change any other bit in the register.
@@ -451,22 +443,16 @@ static bool trap_bvr(struct kvm_vcpu *vcpu,
 }
 
 static int set_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm];
-
-	if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm] = val;
 	return 0;
 }
 
 static int get_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-	const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 *val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm];
-
-	if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	*val = vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm];
 	return 0;
 }
 
@@ -493,23 +479,16 @@ static bool trap_bcr(struct kvm_vcpu *vcpu,
 }
 
 static int set_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm];
-
-	if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
-
+	vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm] = val;
 	return 0;
 }
 
 static int get_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-	const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 *val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm];
-
-	if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	*val = vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm];
 	return 0;
 }
 
@@ -537,22 +516,16 @@ static bool trap_wvr(struct kvm_vcpu *vcpu,
 }
 
 static int set_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm];
-
-	if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm] = val;
 	return 0;
 }
 
 static int get_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-	const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 *val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm];
-
-	if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	*val = vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm];
 	return 0;
 }
 
@@ -579,22 +552,16 @@ static bool trap_wcr(struct kvm_vcpu *vcpu,
 }
 
 static int set_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm];
-
-	if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm] = val;
 	return 0;
 }
 
 static int get_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-	const struct kvm_one_reg *reg, void __user *uaddr)
+		   u64 *val)
 {
-	__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm];
-
-	if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
-		return -EFAULT;
+	*val = vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm];
 	return 0;
 }
 
@@ -1227,16 +1194,9 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
 
 static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 			       const struct sys_reg_desc *rd,
-			       const struct kvm_one_reg *reg, void __user *uaddr)
+			       u64 val)
 {
-	const u64 id = sys_reg_to_index(rd);
 	u8 csv2, csv3;
-	int err;
-	u64 val;
-
-	err = reg_from_user(&val, uaddr, id);
-	if (err)
-		return err;
 
 	/*
 	 * Allow AA64PFR0_EL1.CSV2 to be set from userspace as long as
@@ -1262,7 +1222,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 
 	vcpu->kvm->arch.pfr0_csv2 = csv2;
-	vcpu->kvm->arch.pfr0_csv3 = csv3 ;
+	vcpu->kvm->arch.pfr0_csv3 = csv3;
 
 	return 0;
 }
@@ -1275,27 +1235,17 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
  * to be changed.
  */
 static int __get_id_reg(const struct kvm_vcpu *vcpu,
-			const struct sys_reg_desc *rd, void __user *uaddr,
+			const struct sys_reg_desc *rd, u64 *val,
 			bool raz)
 {
-	const u64 id = sys_reg_to_index(rd);
-	const u64 val = read_id_reg(vcpu, rd, raz);
-
-	return reg_to_user(uaddr, &val, id);
+	*val = read_id_reg(vcpu, rd, raz);
+	return 0;
 }
 
 static int __set_id_reg(const struct kvm_vcpu *vcpu,
-			const struct sys_reg_desc *rd, void __user *uaddr,
+			const struct sys_reg_desc *rd, u64 val,
 			bool raz)
 {
-	const u64 id = sys_reg_to_index(rd);
-	int err;
-	u64 val;
-
-	err = reg_from_user(&val, uaddr, id);
-	if (err)
-		return err;
-
 	/* This is what we mean by invariant: you can't change it. */
 	if (val != read_id_reg(vcpu, rd, raz))
 		return -EINVAL;
@@ -1304,47 +1254,37 @@ static int __set_id_reg(const struct kvm_vcpu *vcpu,
 }
 
 static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		      const struct kvm_one_reg *reg, void __user *uaddr)
+		      u64 *val)
 {
 	bool raz = sysreg_visible_as_raz(vcpu, rd);
 
-	return __get_id_reg(vcpu, rd, uaddr, raz);
+	return __get_id_reg(vcpu, rd, val, raz);
 }
 
 static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		      const struct kvm_one_reg *reg, void __user *uaddr)
+		      u64 val)
 {
 	bool raz = sysreg_visible_as_raz(vcpu, rd);
 
-	return __set_id_reg(vcpu, rd, uaddr, raz);
+	return __set_id_reg(vcpu, rd, val, raz);
 }
 
 static int set_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			  const struct kvm_one_reg *reg, void __user *uaddr)
+			  u64 val)
 {
-	return __set_id_reg(vcpu, rd, uaddr, true);
+	return __set_id_reg(vcpu, rd, val, true);
 }
 
 static int get_raz_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		       const struct kvm_one_reg *reg, void __user *uaddr)
+		       u64 *val)
 {
-	const u64 id = sys_reg_to_index(rd);
-	const u64 val = 0;
-
-	return reg_to_user(uaddr, &val, id);
+	*val = 0;
+	return 0;
 }
 
 static int set_wi_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-		      const struct kvm_one_reg *reg, void __user *uaddr)
+		      u64 val)
 {
-	int err;
-	u64 val;
-
-	/* Perform the access even if we are going to ignore the value */
-	err = reg_from_user(&val, uaddr, sys_reg_to_index(rd));
-	if (err)
-		return err;
-
 	return 0;
 }
 
@@ -2850,17 +2790,26 @@ static int demux_c15_set(u64 id, void __user *uaddr)
 int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
 			 const struct sys_reg_desc table[], unsigned int num)
 {
-	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	u64 __user *uaddr = (u64 __user *)(unsigned long)reg->addr;
 	const struct sys_reg_desc *r;
+	u64 val;
+	int ret;
 
 	r = id_to_sys_reg_desc(vcpu, reg->id, table, num);
 	if (!r)
 		return -ENOENT;
 
-	if (r->get_user)
-		return (r->get_user)(vcpu, r, reg, uaddr);
+	if (r->get_user) {
+		ret = (r->get_user)(vcpu, r, &val);
+	} else {
+		val = __vcpu_sys_reg(vcpu, r->reg);
+		ret = 0;
+	}
+
+	if (!ret)
+		ret = put_user(val, uaddr);
 
-	return reg_to_user(uaddr, &__vcpu_sys_reg(vcpu, r->reg), reg->id);
+	return ret;
 }
 
 int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
@@ -2882,17 +2831,26 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
 			 const struct sys_reg_desc table[], unsigned int num)
 {
-	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
+	u64 __user *uaddr = (u64 __user *)(unsigned long)reg->addr;
 	const struct sys_reg_desc *r;
+	u64 val;
+	int ret;
+
+	if (get_user(val, uaddr))
+		return -EFAULT;
 
 	r = id_to_sys_reg_desc(vcpu, reg->id, table, num);
 	if (!r)
 		return -ENOENT;
 
-	if (r->set_user)
-		return (r->set_user)(vcpu, r, reg, uaddr);
+	if (r->set_user) {
+		ret = (r->set_user)(vcpu, r, val);
+	} else {
+		__vcpu_sys_reg(vcpu, r->reg) = val;
+		ret = 0;
+	}
 
-	return reg_from_user(&__vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
+	return ret;
 }
 
 int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index 4fb6d59e7874..b8b576a2af2b 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -75,9 +75,9 @@ struct sys_reg_desc {
 
 	/* Custom get/set_user functions, fallback to generic if NULL */
 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			const struct kvm_one_reg *reg, void __user *uaddr);
+			u64 *val);
 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			const struct kvm_one_reg *reg, void __user *uaddr);
+			u64 val);
 
 	/* Return mask of REG_* runtime visibility overrides */
 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
-- 
cgit v1.2.3


From 5a420ed9646a934e983358aeba1bf3cd993d1cc5 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 4 Jul 2022 17:55:43 +0100
Subject: KVM: arm64: Get rid of reg_from/to_user()

These helpers are only used by the invariant stuff now, and while
they pretend to support non-64bit registers, this only serves as
a way to scare the casual reviewer...

Replace these helpers with our good friends get/put_user(), and
don't look back.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 30 ++++++------------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 526798524697..379478eecfaa 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -44,8 +44,6 @@
  * 64bit interface.
  */
 
-static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
-static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
 static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
 
 static bool read_from_write_only(struct kvm_vcpu *vcpu,
@@ -2657,21 +2655,7 @@ static struct sys_reg_desc invariant_sys_regs[] = {
 	{ SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 },
 };
 
-static int reg_from_user(u64 *val, const void __user *uaddr, u64 id)
-{
-	if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
-		return -EFAULT;
-	return 0;
-}
-
-static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)
-{
-	if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)
-		return -EFAULT;
-	return 0;
-}
-
-static int get_invariant_sys_reg(u64 id, void __user *uaddr)
+static int get_invariant_sys_reg(u64 id, u64 __user *uaddr)
 {
 	const struct sys_reg_desc *r;
 
@@ -2680,23 +2664,21 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr)
 	if (!r)
 		return -ENOENT;
 
-	return reg_to_user(uaddr, &r->val, id);
+	return put_user(r->val, uaddr);
 }
 
-static int set_invariant_sys_reg(u64 id, void __user *uaddr)
+static int set_invariant_sys_reg(u64 id, u64 __user *uaddr)
 {
 	const struct sys_reg_desc *r;
-	int err;
-	u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
+	u64 val;
 
 	r = get_reg_by_id(id, invariant_sys_regs,
 			  ARRAY_SIZE(invariant_sys_regs));
 	if (!r)
 		return -ENOENT;
 
-	err = reg_from_user(&val, uaddr, id);
-	if (err)
-		return err;
+	if (get_user(val, uaddr))
+		return -EFAULT;
 
 	/* This is what we mean by invariant: you can't change it. */
 	if (r->val != val)
-- 
cgit v1.2.3


From f6dddbb25572218d2e8ab93bfdad20cddeb99b5a Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 4 Jul 2022 10:03:33 +0100
Subject: KVM: arm64: Get rid of find_reg_by_id()

This helper doesn't have a user anymore, let's get rid of it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 11 -----------
 arch/arm64/kvm/sys_regs.h |  5 -----
 2 files changed, 16 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 379478eecfaa..7ab67a7fc0d8 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2577,17 +2577,6 @@ static bool index_to_params(u64 id, struct sys_reg_params *params)
 	}
 }
 
-const struct sys_reg_desc *find_reg_by_id(u64 id,
-					  struct sys_reg_params *params,
-					  const struct sys_reg_desc table[],
-					  unsigned int num)
-{
-	if (!index_to_params(id, params))
-		return NULL;
-
-	return find_reg(params, table, num);
-}
-
 const struct sys_reg_desc *get_reg_by_id(u64 id,
 					 const struct sys_reg_desc table[],
 					 unsigned int num)
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index b8b576a2af2b..49517f58deb5 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -190,11 +190,6 @@ find_reg(const struct sys_reg_params *params, const struct sys_reg_desc table[],
 	return __inline_bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
 }
 
-const struct sys_reg_desc *find_reg_by_id(u64 id,
-					  struct sys_reg_params *params,
-					  const struct sys_reg_desc table[],
-					  unsigned int num);
-
 const struct sys_reg_desc *get_reg_by_id(u64 id,
 					 const struct sys_reg_desc table[],
 					 unsigned int num);
-- 
cgit v1.2.3


From 4274d42716d87d5301fdf67eb799e7db08fe73de Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 4 Jul 2022 18:11:04 +0100
Subject: KVM: arm64: Get rid or outdated comments

Once apon a time, the 32bit KVM/arm port was the reference, while
the arm64 version was the new kid on the block, without a clear
future... This was a long time ago.

"The times, they are a-changing."

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 5 -----
 1 file changed, 5 deletions(-)

(limited to 'arch/arm64/kvm/sys_regs.c')

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 7ab67a7fc0d8..b4fda04413f2 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -34,11 +34,6 @@
 #include "trace.h"
 
 /*
- * All of this file is extremely similar to the ARM coproc.c, but the
- * types are different. My gut feeling is that it should be pretty
- * easy to merge, but that would be an ABI breakage -- again. VFP
- * would also need to be abstracted.
- *
  * For AArch32, we only take care of what is being trapped. Anything
  * that has to do with init and userspace access has to go via the
  * 64bit interface.
-- 
cgit v1.2.3