On Mon, Dec 07, 2015 at 10:53:26AM +0000, Marc Zyngier wrote: > Contrary to the previous patch, the guest entry is fairly different > from its assembly counterpart, mostly because it is only concerned > with saving/restoring the GP registers, and nothing else. > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > arch/arm64/kvm/hyp/Makefile | 1 + > arch/arm64/kvm/hyp/entry.S | 131 ++++++++++++++++++++++++++++++++++++++++++++ > arch/arm64/kvm/hyp/hyp.h | 2 + > 3 files changed, 134 insertions(+) > create mode 100644 arch/arm64/kvm/hyp/entry.S > > diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile > index ec14cac..1e1ff06 100644 > --- a/arch/arm64/kvm/hyp/Makefile > +++ b/arch/arm64/kvm/hyp/Makefile > @@ -7,3 +7,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += sysreg-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += debug-sr.o > +obj-$(CONFIG_KVM_ARM_HOST) += entry.o > diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S > new file mode 100644 > index 0000000..47f3c69 > --- /dev/null > +++ b/arch/arm64/kvm/hyp/entry.S > @@ -0,0 +1,131 @@ > +/* > + * Copyright (C) 2015 - ARM Ltd > + * Author: Marc Zyngier <marc.zyngier@xxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/linkage.h> > + > +#include <asm/asm-offsets.h> > +#include <asm/assembler.h> > +#include <asm/fpsimdmacros.h> > +#include <asm/kvm.h> > +#include <asm/kvm_arm.h> > +#include <asm/kvm_asm.h> > +#include <asm/kvm_mmu.h> > + > +#define CPU_GP_REG_OFFSET(x) (CPU_GP_REGS + x) > +#define CPU_XREG_OFFSET(x) CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x) > + > + .text > + .pushsection .hyp.text, "ax" > + > +.macro save_callee_saved_regs ctxt > + stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] > + stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] > + stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] > + stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)] > + stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)] > + stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)] > +.endm > + > +.macro restore_callee_saved_regs ctxt > + ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] > + ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] > + ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] > + ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)] > + ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)] > + ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)] > +.endm > + > +/* > + * u64 __guest_enter(struct kvm_vcpu *vcpu, > + * struct kvm_cpu_context *host_ctxt); > + */ > +ENTRY(__guest_enter) > + // x0: vcpu > + // x1: host/guest context > + // x2-x18: clobbered by macros > + > + // Store the host regs > + save_callee_saved_regs x1 > + > + // Preserve vcpu & host_ctxt for use at exit time > + stp x0, x1, [sp, #-16]! > + > + add x1, x0, #VCPU_CONTEXT > + > + // Prepare x0-x1 for later restore by pushing them onto the stack > + ldp x2, x3, [x1, #CPU_XREG_OFFSET(0)] > + stp x2, x3, [sp, #-16]! > + > + // x2-x18 > + ldp x2, x3, [x1, #CPU_XREG_OFFSET(2)] > + ldp x4, x5, [x1, #CPU_XREG_OFFSET(4)] > + ldp x6, x7, [x1, #CPU_XREG_OFFSET(6)] > + ldp x8, x9, [x1, #CPU_XREG_OFFSET(8)] > + ldp x10, x11, [x1, #CPU_XREG_OFFSET(10)] > + ldp x12, x13, [x1, #CPU_XREG_OFFSET(12)] > + ldp x14, x15, [x1, #CPU_XREG_OFFSET(14)] > + ldp x16, x17, [x1, #CPU_XREG_OFFSET(16)] > + ldr x18, [x1, #CPU_XREG_OFFSET(18)] > + > + // x19-x29, lr > + restore_callee_saved_regs x1 > + > + // Last bits of the 64bit state > + ldp x0, x1, [sp], #16 > + > + // Do not touch any register after this! > + eret > +ENDPROC(__guest_enter) > + > +ENTRY(__guest_exit) > + // x0: vcpu > + // x1: return code > + // x2-x3: free > + // x4-x29,lr: vcpu regs > + // vcpu x0-x3 on the stack > + > + add x2, x0, #VCPU_CONTEXT > + > + // Compute base to save registers misleading comment again? Or misplaced at least? > + stp x4, x5, [x2, #CPU_XREG_OFFSET(4)] > + stp x6, x7, [x2, #CPU_XREG_OFFSET(6)] > + stp x8, x9, [x2, #CPU_XREG_OFFSET(8)] > + stp x10, x11, [x2, #CPU_XREG_OFFSET(10)] > + stp x12, x13, [x2, #CPU_XREG_OFFSET(12)] > + stp x14, x15, [x2, #CPU_XREG_OFFSET(14)] > + stp x16, x17, [x2, #CPU_XREG_OFFSET(16)] > + str x18, [x2, #CPU_XREG_OFFSET(18)] > + > + ldp x6, x7, [sp], #16 // x2, x3 > + ldp x4, x5, [sp], #16 // x0, x1 > + > + stp x4, x5, [x2, #CPU_XREG_OFFSET(0)] > + stp x6, x7, [x2, #CPU_XREG_OFFSET(2)] > + > + save_callee_saved_regs x2 > + > + // Restore vcpu & host_ctxt from the stack > + // (preserving return code in x1) > + ldp x0, x2, [sp], #16 > + // Now restore the host regs > + restore_callee_saved_regs x2 > + > + mov x0, x1 > + ret > +ENDPROC(__guest_exit) > + > + /* Insert fault handling here */ > diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h > index 454e46f..0809653 100644 > --- a/arch/arm64/kvm/hyp/hyp.h > +++ b/arch/arm64/kvm/hyp/hyp.h > @@ -52,5 +52,7 @@ void __debug_restore_state(struct kvm_vcpu *vcpu, > void __debug_cond_save_host_state(struct kvm_vcpu *vcpu); > void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu); > > +u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt); > + > #endif /* __ARM64_KVM_HYP_H__ */ > > -- > 2.1.4 > Otherwise: Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
