[RFC PATCH 6/7] arm64: KVM: Refactor C-code to access vCPU fp-registers through macros

Fares Mehanna
2024-09-11T14:37:38Z

Unify how KVM accesses vCPU fp-regs by using vcpu_fp_regs(). This is a
prerequisite to move the fp-regs later to be dynamically allocated for vCPUs.

Signed-off-by: Fares Mehanna <faresx@amazon.de>
---
arch/arm64/include/asm/kvm_host.h | 2 ++
arch/arm64/kvm/arm.c | 2 +-
arch/arm64/kvm/fpsimd.c | 2 +-
arch/arm64/kvm/guest.c | 6 +++---
arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ++--
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 4 ++--
arch/arm64/kvm/reset.c | 2 +-
7 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 23a10178d1b0..e8ed2c12479f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -968,6 +968,8 @@ static __always_inline struct user_pt_regs *ctxt_gp_regs(const struct kvm_cpu_co
return regs;
}
#define vcpu_gp_regs(v) (ctxt_gp_regs(&(v)->arch.ctxt))
+#define ctxt_fp_regs(ctxt) (&(ctxt).fp_regs)
+#define vcpu_fp_regs(v) (ctxt_fp_regs(&(v)->arch.ctxt))

/*
* Only use __vcpu_sys_reg/ctxt_sys_reg if you know you want the
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 78c562a060de..7542af3f766a 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2507,7 +2507,7 @@ static void finalize_init_hyp_mode(void)
for_each_possible_cpu(cpu) {
struct user_fpsimd_state *fpsimd_state;

- fpsimd_state = &per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->host_ctxt.fp_regs;
+ fpsimd_state = ctxt_fp_regs(&per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->host_ctxt);
per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->fpsimd_state =
kern_hyp_va(fpsimd_state);
}
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index c53e5b14038d..c27c96ae22e1 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -130,7 +130,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
* Currently we do not support SME guests so SVCR is
* always 0 and we just need a variable to point to.
*/
- fp_state.st = &vcpu->arch.ctxt.fp_regs;
+ fp_state.st = vcpu_fp_regs(vcpu);
fp_state.sve_state = vcpu->arch.sve_state;
fp_state.sve_vl = vcpu->arch.sve_max_vl;
fp_state.sme_state = NULL;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 821a2b7de388..3474874a00a7 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -170,13 +170,13 @@ static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
off -= KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]);
off /= 4;
- return &vcpu->arch.ctxt.fp_regs.vregs[off];
+ return &vcpu_fp_regs(vcpu)->vregs[off];

case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
- return &vcpu->arch.ctxt.fp_regs.fpsr;
+ return &vcpu_fp_regs(vcpu)->fpsr;

case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
- return &vcpu->arch.ctxt.fp_regs.fpcr;
+ return &vcpu_fp_regs(vcpu)->fpcr;

default:
return NULL;
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index d2ed0938fc90..1444bad519db 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -319,7 +319,7 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
*/
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
__sve_restore_state(vcpu_sve_pffr(vcpu),
- &vcpu->arch.ctxt.fp_regs.fpsr,
+ &vcpu_fp_regs(vcpu)->fpsr,
true);

/*
@@ -401,7 +401,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
if (sve_guest)
__hyp_sve_restore_guest(vcpu);
else
- __fpsimd_restore_state(&vcpu->arch.ctxt.fp_regs);
+ __fpsimd_restore_state(vcpu_fp_regs(vcpu));

/* Skip restoring fpexc32 for AArch64 guests */
if (!(read_sysreg(hcr_el2) & HCR_RW))
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index f43d845f3c4e..feb1dd37f2a5 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -32,7 +32,7 @@ static void __hyp_sve_save_guest(struct kvm_vcpu *vcpu)
* on the VL, so use a consistent (i.e., the maximum) guest VL.
*/
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
- __sve_save_state(vcpu_sve_pffr(vcpu), &vcpu->arch.ctxt.fp_regs.fpsr, true);
+ __sve_save_state(vcpu_sve_pffr(vcpu), &vcpu_fp_regs(vcpu)->fpsr, true);
write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
}

@@ -71,7 +71,7 @@ static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
if (vcpu_has_sve(vcpu))
__hyp_sve_save_guest(vcpu);
else
- __fpsimd_save_state(&vcpu->arch.ctxt.fp_regs);
+ __fpsimd_save_state(vcpu_fp_regs(vcpu));

if (system_supports_sve())
__hyp_sve_restore_host();
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 0b0ae5ae7bc2..5f38acf5d156 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -229,7 +229,7 @@ void kvm_reset_vcpu(struct kvm_vcpu *vcpu)

/* Reset core registers */
memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
- memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
+ memset(vcpu_fp_regs(vcpu), 0, sizeof(*vcpu_fp_regs(vcpu)));
vcpu->arch.ctxt.spsr_abt = 0;
vcpu->arch.ctxt.spsr_und = 0;
vcpu->arch.ctxt.spsr_irq = 0;
--
2.40.1