KVM: arm64: Refactor checks for FP state ownership

To avoid direct comparison against the fp_owner enum, add a new
function that performs the check, host_owns_fp_regs(), to
complement the existing guest_owns_fp_regs().

To check for fpsimd state ownership, use the helpers instead of
directly using the enums.

No functional change intended.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 3d65d9413608f3aa88e7621f422f77aae0f5442c..deaa88b972ec41a82e2f6f76540fcfcd290b77c2 100644 (file)
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -587,16 +587,14 @@ static __always_inline u64 kvm_get_reset_cptr_el2(struct kvm_vcpu *vcpu)
        } else if (has_hvhe()) {
                val = (CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN);
 
-               if (!vcpu_has_sve(vcpu) ||
-                   (*host_data_ptr(fp_owner) != FP_STATE_GUEST_OWNED))
+               if (!vcpu_has_sve(vcpu) || !guest_owns_fp_regs())
                        val |= CPACR_EL1_ZEN_EL1EN | CPACR_EL1_ZEN_EL0EN;
                if (cpus_have_final_cap(ARM64_SME))
                        val |= CPACR_EL1_SMEN_EL1EN | CPACR_EL1_SMEN_EL0EN;
        } else {
                val = CPTR_NVHE_EL2_RES1;
 
-               if (vcpu_has_sve(vcpu) &&
-                   (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED))
+               if (vcpu_has_sve(vcpu) && guest_owns_fp_regs())
                        val |= CPTR_EL2_TZ;
                if (cpus_have_final_cap(ARM64_SME))
                        val &= ~CPTR_EL2_TSM;

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2889e1d8a8c1250585672907549a56888113f117..4609d1b9dddede6355c910238e621ae30fb7a408 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1213,6 +1213,12 @@ static inline bool guest_owns_fp_regs(void)
        return *host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED;
 }
 
+/* Check whether the FP regs are owned by the host */
+static inline bool host_owns_fp_regs(void)
+{
+       return *host_data_ptr(fp_owner) == FP_STATE_HOST_OWNED;
+}
+
 static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt)
 {
        /* The host's MPIDR is immutable, so let's set it up at boot time */

diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 7507dcc4e553bbb9bac54059535e1500e9c187c1..d5837d65e4a1b6566a3834a3899d9714e064d534 100644 (file)
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -141,8 +141,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
 
        WARN_ON_ONCE(!irqs_disabled());
 
-       if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) {
-
+       if (guest_owns_fp_regs()) {
                /*
                 * Currently we do not support SME guests so SVCR is
                 * always 0 and we just need a variable to point to.
@@ -195,7 +194,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
                isb();
        }
 
-       if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) {
+       if (guest_owns_fp_regs()) {
                if (vcpu_has_sve(vcpu)) {
                        __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR);
 

diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 38961b6b1a18ed1efc700d147356e535edfb7d01..38b4e2623b020c7ecffca0bcd5acad4757730c15 100644 (file)
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -370,7 +370,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
        isb();
 
        /* Write out the host state if it's in the registers */
-       if (*host_data_ptr(fp_owner) == FP_STATE_HOST_OWNED)
+       if (host_owns_fp_regs())
                __fpsimd_save_state(*host_data_ptr(fpsimd_state));
 
        /* Restore the guest state */

diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 1b22654a31809dad911e2879b3e5fced3dc8e130..5d2d4d6465e8ca0b753c2433e42b2e0e9a6ec0c4 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -337,7 +337,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 
        __sysreg_restore_state_nvhe(host_ctxt);
 
-       if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED)
+       if (guest_owns_fp_regs())
                __fpsimd_save_fpexc32(vcpu);
 
        __debug_switch_to_host(vcpu);

diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 7286db75b8d68d261725409bb2673522da626aab..93f78df8b0f62dbf447a766ba22bba2a2f6164ee 100644 (file)
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -258,7 +258,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 
        sysreg_restore_host_state_vhe(host_ctxt);
 
-       if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED)
+       if (guest_owns_fp_regs())
                __fpsimd_save_fpexc32(vcpu);
 
        __debug_switch_to_host(vcpu);