[PATCH v2 14/17] KVM: arm64: Disintegrate SPSR array

Marc Zyngier
2020-06-15T13:33:49Z

As we're about to move SPSR_EL1 into the VNCR page, we need to
disassociate it from the rest of the 32bit cruft. Let's break
the array into individual fields.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_emulate.h | 4 ++--
arch/arm64/include/asm/kvm_host.h | 6 ++++-
arch/arm64/kvm/guest.c | 19 +++++++++++----
arch/arm64/kvm/hyp/sysreg-sr.c | 28 ++++++++--------------
arch/arm64/kvm/regmap.c | 35 +++++++++++++++++++++++++---
5 files changed, 63 insertions(+), 29 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 3b1d32c639c2..83271a4d6c59 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -176,7 +176,7 @@ static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
if (vcpu->arch.sysregs_loaded_on_cpu)
return read_sysreg_el1(SYS_SPSR);
else
- return vcpu->arch.ctxt.spsr[KVM_SPSR_EL1];
+ return vcpu->arch.ctxt.spsr_el1;
}

static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
@@ -189,7 +189,7 @@ static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
if (vcpu->arch.sysregs_loaded_on_cpu)
write_sysreg_el1(v, SYS_SPSR);
else
- vcpu->arch.ctxt.spsr[KVM_SPSR_EL1] = v;
+ vcpu->arch.ctxt.spsr_el1 = v;
}

/*
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 22ca60408dea..7ab6f5b5bf5d 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -241,7 +241,11 @@ enum vcpu_sysreg {
struct kvm_cpu_context {
struct user_pt_regs regs; /* sp = sp_el0 */

- u64 spsr[KVM_NR_SPSR];
+ u64 spsr_el1; /* aka spsr_svc */
+ u64 spsr_abt;
+ u64 spsr_und;
+ u64 spsr_irq;
+ u64 spsr_fiq;

struct user_fpsimd_state fp_regs;

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index d614716e073b..70215f3a6f89 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -134,11 +134,20 @@ static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
case KVM_REG_ARM_CORE_REG(elr_el1):
return __ctxt_sys_reg(&vcpu->arch.ctxt, ELR_EL1);

- case KVM_REG_ARM_CORE_REG(spsr[0]) ...
- KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
- off -= KVM_REG_ARM_CORE_REG(spsr[0]);
- off /= 2;
- return &vcpu->arch.ctxt.spsr[off];
+ case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_EL1]):
+ return &vcpu->arch.ctxt.spsr_el1;
+
+ case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_ABT]):
+ return &vcpu->arch.ctxt.spsr_abt;
+
+ case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_UND]):
+ return &vcpu->arch.ctxt.spsr_und;
+
+ case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_IRQ]):
+ return &vcpu->arch.ctxt.spsr_irq;
+
+ case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_FIQ]):
+ return &vcpu->arch.ctxt.spsr_fiq;

case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 252d5c1240a3..4f54c1d28ff4 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -57,7 +57,7 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)

ctxt_sys_reg(ctxt, SP_EL1) = read_sysreg(sp_el1);
ctxt_sys_reg(ctxt, ELR_EL1) = read_sysreg_el1(SYS_ELR);
- ctxt->spsr[KVM_SPSR_EL1] = read_sysreg_el1(SYS_SPSR);
+ ctxt->spsr_el1 = read_sysreg_el1(SYS_SPSR);
}

static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
@@ -157,7 +157,7 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)

write_sysreg(ctxt_sys_reg(ctxt, SP_EL1), sp_el1);
write_sysreg_el1(ctxt_sys_reg(ctxt, ELR_EL1), SYS_ELR);
- write_sysreg_el1(ctxt->spsr[KVM_SPSR_EL1], SYS_SPSR);
+ write_sysreg_el1(ctxt->spsr_el1, SYS_SPSR);
}

static void __hyp_text
@@ -210,17 +210,13 @@ NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);

void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
{
- u64 *spsr;
-
if (!vcpu_el1_is_32bit(vcpu))
return;

- spsr = vcpu->arch.ctxt.spsr;
-
- spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
- spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
- spsr[KVM_SPSR_IRQ] = read_sysreg(spsr_irq);
- spsr[KVM_SPSR_FIQ] = read_sysreg(spsr_fiq);
+ vcpu->arch.ctxt.spsr_abt = read_sysreg(spsr_abt);
+ vcpu->arch.ctxt.spsr_und = read_sysreg(spsr_und);
+ vcpu->arch.ctxt.spsr_irq = read_sysreg(spsr_irq);
+ vcpu->arch.ctxt.spsr_fiq = read_sysreg(spsr_fiq);

__vcpu_sys_reg(vcpu, DACR32_EL2) = read_sysreg(dacr32_el2);
__vcpu_sys_reg(vcpu, IFSR32_EL2) = read_sysreg(ifsr32_el2);
@@ -231,17 +227,13 @@ void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)

void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
{
- u64 *spsr;
-
if (!vcpu_el1_is_32bit(vcpu))
return;

- spsr = vcpu->arch.ctxt.spsr;
-
- write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
- write_sysreg(spsr[KVM_SPSR_UND], spsr_und);
- write_sysreg(spsr[KVM_SPSR_IRQ], spsr_irq);
- write_sysreg(spsr[KVM_SPSR_FIQ], spsr_fiq);
+ write_sysreg(vcpu->arch.ctxt.spsr_abt, spsr_abt);
+ write_sysreg(vcpu->arch.ctxt.spsr_und, spsr_und);
+ write_sysreg(vcpu->arch.ctxt.spsr_irq, spsr_irq);
+ write_sysreg(vcpu->arch.ctxt.spsr_fiq, spsr_fiq);

write_sysreg(__vcpu_sys_reg(vcpu, DACR32_EL2), dacr32_el2);
write_sysreg(__vcpu_sys_reg(vcpu, IFSR32_EL2), ifsr32_el2);
diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c
index b1596f314087..97c110810527 100644
--- a/arch/arm64/kvm/regmap.c
+++ b/arch/arm64/kvm/regmap.c
@@ -147,8 +147,20 @@ unsigned long vcpu_read_spsr32(const struct kvm_vcpu *vcpu)
{
int spsr_idx = vcpu_spsr32_mode(vcpu);

- if (!vcpu->arch.sysregs_loaded_on_cpu)
- return vcpu->arch.ctxt.spsr[spsr_idx];
+ if (!vcpu->arch.sysregs_loaded_on_cpu) {
+ switch (spsr_idx) {
+ case KVM_SPSR_SVC:
+ return vcpu->arch.ctxt.spsr_el1;
+ case KVM_SPSR_ABT:
+ return vcpu->arch.ctxt.spsr_abt;
+ case KVM_SPSR_UND:
+ return vcpu->arch.ctxt.spsr_und;
+ case KVM_SPSR_IRQ:
+ return vcpu->arch.ctxt.spsr_irq;
+ case KVM_SPSR_FIQ:
+ return vcpu->arch.ctxt.spsr_fiq;
+ }
+ }

switch (spsr_idx) {
case KVM_SPSR_SVC:
@@ -171,7 +183,24 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
int spsr_idx = vcpu_spsr32_mode(vcpu);

if (!vcpu->arch.sysregs_loaded_on_cpu) {
- vcpu->arch.ctxt.spsr[spsr_idx] = v;
+ switch (spsr_idx) {
+ case KVM_SPSR_SVC:
+ vcpu->arch.ctxt.spsr_el1 = v;
+ break;
+ case KVM_SPSR_ABT:
+ vcpu->arch.ctxt.spsr_abt = v;
+ break;
+ case KVM_SPSR_UND:
+ vcpu->arch.ctxt.spsr_und = v;
+ break;
+ case KVM_SPSR_IRQ:
+ vcpu->arch.ctxt.spsr_irq = v;
+ break;
+ case KVM_SPSR_FIQ:
+ vcpu->arch.ctxt.spsr_fiq = v;
+ break;
+ }
+
return;
}

--
2.27.0