lkml.org 
[lkml]   [2019]   [Dec]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v10 15/19] RISC-V: KVM: FP lazy save/restore
Date
From: Atish Patra <atish.patra@wdc.com>

This patch adds floating point (F and D extension) context save/restore
for guest VCPUs. The FP context is saved and restored lazily only when
kernel enter/exits the in-kernel run loop and not during the KVM world
switch. This way FP save/restore has minimal impact on KVM performance.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
---
arch/riscv/include/asm/kvm_host.h | 5 +
arch/riscv/kernel/asm-offsets.c | 72 +++++++++++++
arch/riscv/kvm/vcpu.c | 81 ++++++++++++++
arch/riscv/kvm/vcpu_switch.S | 174 ++++++++++++++++++++++++++++++
4 files changed, 332 insertions(+)

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index b547f79c2e49..56a8ab9772ae 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -120,6 +120,7 @@ struct kvm_cpu_context {
unsigned long sepc;
unsigned long sstatus;
unsigned long hstatus;
+ union __riscv_fp_state fp;
};

struct kvm_vcpu_csr {
@@ -237,6 +238,10 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
unsigned long htval, unsigned long htinst);

void __kvm_riscv_switch_to(struct kvm_vcpu_arch *vcpu_arch);
+void __kvm_riscv_fp_f_save(struct kvm_cpu_context *context);
+void __kvm_riscv_fp_f_restore(struct kvm_cpu_context *context);
+void __kvm_riscv_fp_d_save(struct kvm_cpu_context *context);
+void __kvm_riscv_fp_d_restore(struct kvm_cpu_context *context);

int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq);
int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq);
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index 3a230882b91e..9016e4e27f3c 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -185,6 +185,78 @@ void asm_offsets(void)
OFFSET(KVM_ARCH_HOST_SSCRATCH, kvm_vcpu_arch, host_sscratch);
OFFSET(KVM_ARCH_HOST_STVEC, kvm_vcpu_arch, host_stvec);

+ /* F extension */
+
+ OFFSET(KVM_ARCH_FP_F_F0, kvm_cpu_context, fp.f.f[0]);
+ OFFSET(KVM_ARCH_FP_F_F1, kvm_cpu_context, fp.f.f[1]);
+ OFFSET(KVM_ARCH_FP_F_F2, kvm_cpu_context, fp.f.f[2]);
+ OFFSET(KVM_ARCH_FP_F_F3, kvm_cpu_context, fp.f.f[3]);
+ OFFSET(KVM_ARCH_FP_F_F4, kvm_cpu_context, fp.f.f[4]);
+ OFFSET(KVM_ARCH_FP_F_F5, kvm_cpu_context, fp.f.f[5]);
+ OFFSET(KVM_ARCH_FP_F_F6, kvm_cpu_context, fp.f.f[6]);
+ OFFSET(KVM_ARCH_FP_F_F7, kvm_cpu_context, fp.f.f[7]);
+ OFFSET(KVM_ARCH_FP_F_F8, kvm_cpu_context, fp.f.f[8]);
+ OFFSET(KVM_ARCH_FP_F_F9, kvm_cpu_context, fp.f.f[9]);
+ OFFSET(KVM_ARCH_FP_F_F10, kvm_cpu_context, fp.f.f[10]);
+ OFFSET(KVM_ARCH_FP_F_F11, kvm_cpu_context, fp.f.f[11]);
+ OFFSET(KVM_ARCH_FP_F_F12, kvm_cpu_context, fp.f.f[12]);
+ OFFSET(KVM_ARCH_FP_F_F13, kvm_cpu_context, fp.f.f[13]);
+ OFFSET(KVM_ARCH_FP_F_F14, kvm_cpu_context, fp.f.f[14]);
+ OFFSET(KVM_ARCH_FP_F_F15, kvm_cpu_context, fp.f.f[15]);
+ OFFSET(KVM_ARCH_FP_F_F16, kvm_cpu_context, fp.f.f[16]);
+ OFFSET(KVM_ARCH_FP_F_F17, kvm_cpu_context, fp.f.f[17]);
+ OFFSET(KVM_ARCH_FP_F_F18, kvm_cpu_context, fp.f.f[18]);
+ OFFSET(KVM_ARCH_FP_F_F19, kvm_cpu_context, fp.f.f[19]);
+ OFFSET(KVM_ARCH_FP_F_F20, kvm_cpu_context, fp.f.f[20]);
+ OFFSET(KVM_ARCH_FP_F_F21, kvm_cpu_context, fp.f.f[21]);
+ OFFSET(KVM_ARCH_FP_F_F22, kvm_cpu_context, fp.f.f[22]);
+ OFFSET(KVM_ARCH_FP_F_F23, kvm_cpu_context, fp.f.f[23]);
+ OFFSET(KVM_ARCH_FP_F_F24, kvm_cpu_context, fp.f.f[24]);
+ OFFSET(KVM_ARCH_FP_F_F25, kvm_cpu_context, fp.f.f[25]);
+ OFFSET(KVM_ARCH_FP_F_F26, kvm_cpu_context, fp.f.f[26]);
+ OFFSET(KVM_ARCH_FP_F_F27, kvm_cpu_context, fp.f.f[27]);
+ OFFSET(KVM_ARCH_FP_F_F28, kvm_cpu_context, fp.f.f[28]);
+ OFFSET(KVM_ARCH_FP_F_F29, kvm_cpu_context, fp.f.f[29]);
+ OFFSET(KVM_ARCH_FP_F_F30, kvm_cpu_context, fp.f.f[30]);
+ OFFSET(KVM_ARCH_FP_F_F31, kvm_cpu_context, fp.f.f[31]);
+ OFFSET(KVM_ARCH_FP_F_FCSR, kvm_cpu_context, fp.f.fcsr);
+
+ /* D extension */
+
+ OFFSET(KVM_ARCH_FP_D_F0, kvm_cpu_context, fp.d.f[0]);
+ OFFSET(KVM_ARCH_FP_D_F1, kvm_cpu_context, fp.d.f[1]);
+ OFFSET(KVM_ARCH_FP_D_F2, kvm_cpu_context, fp.d.f[2]);
+ OFFSET(KVM_ARCH_FP_D_F3, kvm_cpu_context, fp.d.f[3]);
+ OFFSET(KVM_ARCH_FP_D_F4, kvm_cpu_context, fp.d.f[4]);
+ OFFSET(KVM_ARCH_FP_D_F5, kvm_cpu_context, fp.d.f[5]);
+ OFFSET(KVM_ARCH_FP_D_F6, kvm_cpu_context, fp.d.f[6]);
+ OFFSET(KVM_ARCH_FP_D_F7, kvm_cpu_context, fp.d.f[7]);
+ OFFSET(KVM_ARCH_FP_D_F8, kvm_cpu_context, fp.d.f[8]);
+ OFFSET(KVM_ARCH_FP_D_F9, kvm_cpu_context, fp.d.f[9]);
+ OFFSET(KVM_ARCH_FP_D_F10, kvm_cpu_context, fp.d.f[10]);
+ OFFSET(KVM_ARCH_FP_D_F11, kvm_cpu_context, fp.d.f[11]);
+ OFFSET(KVM_ARCH_FP_D_F12, kvm_cpu_context, fp.d.f[12]);
+ OFFSET(KVM_ARCH_FP_D_F13, kvm_cpu_context, fp.d.f[13]);
+ OFFSET(KVM_ARCH_FP_D_F14, kvm_cpu_context, fp.d.f[14]);
+ OFFSET(KVM_ARCH_FP_D_F15, kvm_cpu_context, fp.d.f[15]);
+ OFFSET(KVM_ARCH_FP_D_F16, kvm_cpu_context, fp.d.f[16]);
+ OFFSET(KVM_ARCH_FP_D_F17, kvm_cpu_context, fp.d.f[17]);
+ OFFSET(KVM_ARCH_FP_D_F18, kvm_cpu_context, fp.d.f[18]);
+ OFFSET(KVM_ARCH_FP_D_F19, kvm_cpu_context, fp.d.f[19]);
+ OFFSET(KVM_ARCH_FP_D_F20, kvm_cpu_context, fp.d.f[20]);
+ OFFSET(KVM_ARCH_FP_D_F21, kvm_cpu_context, fp.d.f[21]);
+ OFFSET(KVM_ARCH_FP_D_F22, kvm_cpu_context, fp.d.f[22]);
+ OFFSET(KVM_ARCH_FP_D_F23, kvm_cpu_context, fp.d.f[23]);
+ OFFSET(KVM_ARCH_FP_D_F24, kvm_cpu_context, fp.d.f[24]);
+ OFFSET(KVM_ARCH_FP_D_F25, kvm_cpu_context, fp.d.f[25]);
+ OFFSET(KVM_ARCH_FP_D_F26, kvm_cpu_context, fp.d.f[26]);
+ OFFSET(KVM_ARCH_FP_D_F27, kvm_cpu_context, fp.d.f[27]);
+ OFFSET(KVM_ARCH_FP_D_F28, kvm_cpu_context, fp.d.f[28]);
+ OFFSET(KVM_ARCH_FP_D_F29, kvm_cpu_context, fp.d.f[29]);
+ OFFSET(KVM_ARCH_FP_D_F30, kvm_cpu_context, fp.d.f[30]);
+ OFFSET(KVM_ARCH_FP_D_F31, kvm_cpu_context, fp.d.f[31]);
+ OFFSET(KVM_ARCH_FP_D_FCSR, kvm_cpu_context, fp.d.fcsr);
+
/*
* THREAD_{F,X}* might be larger than a S-type offset can handle, but
* these are used in performance-sensitive assembly so we can't resort
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index a49e1695f11b..a3f1a9d59afc 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -31,6 +31,76 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ NULL }
};

+#ifdef CONFIG_FPU
+static void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu)
+{
+ unsigned long isa = vcpu->arch.isa;
+ struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
+
+ cntx->sstatus &= ~SR_FS;
+ if (riscv_isa_extension_available(&isa, f) ||
+ riscv_isa_extension_available(&isa, d))
+ cntx->sstatus |= SR_FS_INITIAL;
+ else
+ cntx->sstatus |= SR_FS_OFF;
+}
+
+static void kvm_riscv_vcpu_fp_clean(struct kvm_cpu_context *cntx)
+{
+ cntx->sstatus &= ~SR_FS;
+ cntx->sstatus |= SR_FS_CLEAN;
+}
+
+static void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
+ unsigned long isa)
+{
+ if ((cntx->sstatus & SR_FS) == SR_FS_DIRTY) {
+ if (riscv_isa_extension_available(&isa, d))
+ __kvm_riscv_fp_d_save(cntx);
+ else if (riscv_isa_extension_available(&isa, f))
+ __kvm_riscv_fp_f_save(cntx);
+ kvm_riscv_vcpu_fp_clean(cntx);
+ }
+}
+
+static void kvm_riscv_vcpu_guest_fp_restore(struct kvm_cpu_context *cntx,
+ unsigned long isa)
+{
+ if ((cntx->sstatus & SR_FS) != SR_FS_OFF) {
+ if (riscv_isa_extension_available(&isa, d))
+ __kvm_riscv_fp_d_restore(cntx);
+ else if (riscv_isa_extension_available(&isa, f))
+ __kvm_riscv_fp_f_restore(cntx);
+ kvm_riscv_vcpu_fp_clean(cntx);
+ }
+}
+
+static void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx)
+{
+ /* No need to check host sstatus as it can be modified outside */
+ if (riscv_isa_extension_available(NULL, d))
+ __kvm_riscv_fp_d_save(cntx);
+ else if (riscv_isa_extension_available(NULL, f))
+ __kvm_riscv_fp_f_save(cntx);
+}
+
+static void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx)
+{
+ if (riscv_isa_extension_available(NULL, d))
+ __kvm_riscv_fp_d_restore(cntx);
+ else if (riscv_isa_extension_available(NULL, f))
+ __kvm_riscv_fp_f_restore(cntx);
+}
+#else
+static void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu) {}
+static void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
+ unsigned long isa) {}
+static void kvm_riscv_vcpu_guest_fp_restore(struct kvm_cpu_context *cntx,
+ unsigned long isa) {}
+static void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx) {}
+static void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx) {}
+#endif
+
#define KVM_RISCV_ISA_ALLOWED (riscv_isa_extension_mask(a) | \
riscv_isa_extension_mask(c) | \
riscv_isa_extension_mask(d) | \
@@ -51,6 +121,8 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)

memcpy(cntx, reset_cntx, sizeof(*cntx));

+ kvm_riscv_vcpu_fp_reset(vcpu);
+
kvm_riscv_vcpu_timer_reset(vcpu);

WRITE_ONCE(vcpu->arch.irqs_pending, 0);
@@ -216,6 +288,7 @@ static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu,
vcpu->arch.isa = reg_val;
vcpu->arch.isa &= riscv_isa_extension_base(NULL);
vcpu->arch.isa &= KVM_RISCV_ISA_ALLOWED;
+ kvm_riscv_vcpu_fp_reset(vcpu);
} else {
return -ENOTSUPP;
}
@@ -620,6 +693,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)

kvm_riscv_vcpu_timer_restore(vcpu);

+ kvm_riscv_vcpu_host_fp_save(&vcpu->arch.host_context);
+ kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context,
+ vcpu->arch.isa);
+
vcpu->cpu = cpu;
}

@@ -629,6 +706,10 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)

vcpu->cpu = -1;

+ kvm_riscv_vcpu_guest_fp_save(&vcpu->arch.guest_context,
+ vcpu->arch.isa);
+ kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context);
+
csr_write(CSR_HGATP, 0);

csr->vsstatus = csr_read(CSR_VSSTATUS);
diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S
index 04b318b9eef8..20104b42e833 100644
--- a/arch/riscv/kvm/vcpu_switch.S
+++ b/arch/riscv/kvm/vcpu_switch.S
@@ -206,3 +206,177 @@ ENTRY(__kvm_riscv_unpriv_trap)
csrr a0, CSR_SCAUSE
sret
ENDPROC(__kvm_riscv_unpriv_trap)
+
+#ifdef CONFIG_FPU
+ .align 3
+ .global __kvm_riscv_fp_f_save
+__kvm_riscv_fp_f_save:
+ csrr t2, CSR_SSTATUS
+ li t1, SR_FS
+ csrs CSR_SSTATUS, t1
+ frcsr t0
+ fsw f0, KVM_ARCH_FP_F_F0(a0)
+ fsw f1, KVM_ARCH_FP_F_F1(a0)
+ fsw f2, KVM_ARCH_FP_F_F2(a0)
+ fsw f3, KVM_ARCH_FP_F_F3(a0)
+ fsw f4, KVM_ARCH_FP_F_F4(a0)
+ fsw f5, KVM_ARCH_FP_F_F5(a0)
+ fsw f6, KVM_ARCH_FP_F_F6(a0)
+ fsw f7, KVM_ARCH_FP_F_F7(a0)
+ fsw f8, KVM_ARCH_FP_F_F8(a0)
+ fsw f9, KVM_ARCH_FP_F_F9(a0)
+ fsw f10, KVM_ARCH_FP_F_F10(a0)
+ fsw f11, KVM_ARCH_FP_F_F11(a0)
+ fsw f12, KVM_ARCH_FP_F_F12(a0)
+ fsw f13, KVM_ARCH_FP_F_F13(a0)
+ fsw f14, KVM_ARCH_FP_F_F14(a0)
+ fsw f15, KVM_ARCH_FP_F_F15(a0)
+ fsw f16, KVM_ARCH_FP_F_F16(a0)
+ fsw f17, KVM_ARCH_FP_F_F17(a0)
+ fsw f18, KVM_ARCH_FP_F_F18(a0)
+ fsw f19, KVM_ARCH_FP_F_F19(a0)
+ fsw f20, KVM_ARCH_FP_F_F20(a0)
+ fsw f21, KVM_ARCH_FP_F_F21(a0)
+ fsw f22, KVM_ARCH_FP_F_F22(a0)
+ fsw f23, KVM_ARCH_FP_F_F23(a0)
+ fsw f24, KVM_ARCH_FP_F_F24(a0)
+ fsw f25, KVM_ARCH_FP_F_F25(a0)
+ fsw f26, KVM_ARCH_FP_F_F26(a0)
+ fsw f27, KVM_ARCH_FP_F_F27(a0)
+ fsw f28, KVM_ARCH_FP_F_F28(a0)
+ fsw f29, KVM_ARCH_FP_F_F29(a0)
+ fsw f30, KVM_ARCH_FP_F_F30(a0)
+ fsw f31, KVM_ARCH_FP_F_F31(a0)
+ sw t0, KVM_ARCH_FP_F_FCSR(a0)
+ csrw CSR_SSTATUS, t2
+ ret
+
+ .align 3
+ .global __kvm_riscv_fp_d_save
+__kvm_riscv_fp_d_save:
+ csrr t2, CSR_SSTATUS
+ li t1, SR_FS
+ csrs CSR_SSTATUS, t1
+ frcsr t0
+ fsd f0, KVM_ARCH_FP_D_F0(a0)
+ fsd f1, KVM_ARCH_FP_D_F1(a0)
+ fsd f2, KVM_ARCH_FP_D_F2(a0)
+ fsd f3, KVM_ARCH_FP_D_F3(a0)
+ fsd f4, KVM_ARCH_FP_D_F4(a0)
+ fsd f5, KVM_ARCH_FP_D_F5(a0)
+ fsd f6, KVM_ARCH_FP_D_F6(a0)
+ fsd f7, KVM_ARCH_FP_D_F7(a0)
+ fsd f8, KVM_ARCH_FP_D_F8(a0)
+ fsd f9, KVM_ARCH_FP_D_F9(a0)
+ fsd f10, KVM_ARCH_FP_D_F10(a0)
+ fsd f11, KVM_ARCH_FP_D_F11(a0)
+ fsd f12, KVM_ARCH_FP_D_F12(a0)
+ fsd f13, KVM_ARCH_FP_D_F13(a0)
+ fsd f14, KVM_ARCH_FP_D_F14(a0)
+ fsd f15, KVM_ARCH_FP_D_F15(a0)
+ fsd f16, KVM_ARCH_FP_D_F16(a0)
+ fsd f17, KVM_ARCH_FP_D_F17(a0)
+ fsd f18, KVM_ARCH_FP_D_F18(a0)
+ fsd f19, KVM_ARCH_FP_D_F19(a0)
+ fsd f20, KVM_ARCH_FP_D_F20(a0)
+ fsd f21, KVM_ARCH_FP_D_F21(a0)
+ fsd f22, KVM_ARCH_FP_D_F22(a0)
+ fsd f23, KVM_ARCH_FP_D_F23(a0)
+ fsd f24, KVM_ARCH_FP_D_F24(a0)
+ fsd f25, KVM_ARCH_FP_D_F25(a0)
+ fsd f26, KVM_ARCH_FP_D_F26(a0)
+ fsd f27, KVM_ARCH_FP_D_F27(a0)
+ fsd f28, KVM_ARCH_FP_D_F28(a0)
+ fsd f29, KVM_ARCH_FP_D_F29(a0)
+ fsd f30, KVM_ARCH_FP_D_F30(a0)
+ fsd f31, KVM_ARCH_FP_D_F31(a0)
+ sw t0, KVM_ARCH_FP_D_FCSR(a0)
+ csrw CSR_SSTATUS, t2
+ ret
+
+ .align 3
+ .global __kvm_riscv_fp_f_restore
+__kvm_riscv_fp_f_restore:
+ csrr t2, CSR_SSTATUS
+ li t1, SR_FS
+ lw t0, KVM_ARCH_FP_F_FCSR(a0)
+ csrs CSR_SSTATUS, t1
+ flw f0, KVM_ARCH_FP_F_F0(a0)
+ flw f1, KVM_ARCH_FP_F_F1(a0)
+ flw f2, KVM_ARCH_FP_F_F2(a0)
+ flw f3, KVM_ARCH_FP_F_F3(a0)
+ flw f4, KVM_ARCH_FP_F_F4(a0)
+ flw f5, KVM_ARCH_FP_F_F5(a0)
+ flw f6, KVM_ARCH_FP_F_F6(a0)
+ flw f7, KVM_ARCH_FP_F_F7(a0)
+ flw f8, KVM_ARCH_FP_F_F8(a0)
+ flw f9, KVM_ARCH_FP_F_F9(a0)
+ flw f10, KVM_ARCH_FP_F_F10(a0)
+ flw f11, KVM_ARCH_FP_F_F11(a0)
+ flw f12, KVM_ARCH_FP_F_F12(a0)
+ flw f13, KVM_ARCH_FP_F_F13(a0)
+ flw f14, KVM_ARCH_FP_F_F14(a0)
+ flw f15, KVM_ARCH_FP_F_F15(a0)
+ flw f16, KVM_ARCH_FP_F_F16(a0)
+ flw f17, KVM_ARCH_FP_F_F17(a0)
+ flw f18, KVM_ARCH_FP_F_F18(a0)
+ flw f19, KVM_ARCH_FP_F_F19(a0)
+ flw f20, KVM_ARCH_FP_F_F20(a0)
+ flw f21, KVM_ARCH_FP_F_F21(a0)
+ flw f22, KVM_ARCH_FP_F_F22(a0)
+ flw f23, KVM_ARCH_FP_F_F23(a0)
+ flw f24, KVM_ARCH_FP_F_F24(a0)
+ flw f25, KVM_ARCH_FP_F_F25(a0)
+ flw f26, KVM_ARCH_FP_F_F26(a0)
+ flw f27, KVM_ARCH_FP_F_F27(a0)
+ flw f28, KVM_ARCH_FP_F_F28(a0)
+ flw f29, KVM_ARCH_FP_F_F29(a0)
+ flw f30, KVM_ARCH_FP_F_F30(a0)
+ flw f31, KVM_ARCH_FP_F_F31(a0)
+ fscsr t0
+ csrw CSR_SSTATUS, t2
+ ret
+
+ .align 3
+ .global __kvm_riscv_fp_d_restore
+__kvm_riscv_fp_d_restore:
+ csrr t2, CSR_SSTATUS
+ li t1, SR_FS
+ lw t0, KVM_ARCH_FP_D_FCSR(a0)
+ csrs CSR_SSTATUS, t1
+ fld f0, KVM_ARCH_FP_D_F0(a0)
+ fld f1, KVM_ARCH_FP_D_F1(a0)
+ fld f2, KVM_ARCH_FP_D_F2(a0)
+ fld f3, KVM_ARCH_FP_D_F3(a0)
+ fld f4, KVM_ARCH_FP_D_F4(a0)
+ fld f5, KVM_ARCH_FP_D_F5(a0)
+ fld f6, KVM_ARCH_FP_D_F6(a0)
+ fld f7, KVM_ARCH_FP_D_F7(a0)
+ fld f8, KVM_ARCH_FP_D_F8(a0)
+ fld f9, KVM_ARCH_FP_D_F9(a0)
+ fld f10, KVM_ARCH_FP_D_F10(a0)
+ fld f11, KVM_ARCH_FP_D_F11(a0)
+ fld f12, KVM_ARCH_FP_D_F12(a0)
+ fld f13, KVM_ARCH_FP_D_F13(a0)
+ fld f14, KVM_ARCH_FP_D_F14(a0)
+ fld f15, KVM_ARCH_FP_D_F15(a0)
+ fld f16, KVM_ARCH_FP_D_F16(a0)
+ fld f17, KVM_ARCH_FP_D_F17(a0)
+ fld f18, KVM_ARCH_FP_D_F18(a0)
+ fld f19, KVM_ARCH_FP_D_F19(a0)
+ fld f20, KVM_ARCH_FP_D_F20(a0)
+ fld f21, KVM_ARCH_FP_D_F21(a0)
+ fld f22, KVM_ARCH_FP_D_F22(a0)
+ fld f23, KVM_ARCH_FP_D_F23(a0)
+ fld f24, KVM_ARCH_FP_D_F24(a0)
+ fld f25, KVM_ARCH_FP_D_F25(a0)
+ fld f26, KVM_ARCH_FP_D_F26(a0)
+ fld f27, KVM_ARCH_FP_D_F27(a0)
+ fld f28, KVM_ARCH_FP_D_F28(a0)
+ fld f29, KVM_ARCH_FP_D_F29(a0)
+ fld f30, KVM_ARCH_FP_D_F30(a0)
+ fld f31, KVM_ARCH_FP_D_F31(a0)
+ fscsr t0
+ csrw CSR_SSTATUS, t2
+ ret
+#endif
--
2.17.1
\
 
 \ /
  Last update: 2019-12-23 12:37    [W:0.164 / U:8.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site