[v11,27/31] LoongArch: KVM: Implement vcpu world switch

Message ID	20230522031217.956464-28-zhaotianrui@loongson.cn (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@vger.kernel.org> From: Tianrui Zhao <zhaotianrui@loongson.cn> To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com>, Huacai Chen <chenhuacai@kernel.org>, WANG Xuerui <kernel@xen0n.name>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, loongarch@lists.linux.dev, Jens Axboe <axboe@kernel.dk>, Mark Brown <broonie@kernel.org>, Alex Deucher <alexander.deucher@amd.com>, Oliver Upton <oliver.upton@linux.dev>, maobibo@loongson.cn, Xi Ruoyao <xry111@xry111.site>, zhaotianrui@loongson.cn Subject: [PATCH v11 27/31] LoongArch: KVM: Implement vcpu world switch Date: Mon, 22 May 2023 11:12:13 +0800 Message-Id: <20230522031217.956464-28-zhaotianrui@loongson.cn> In-Reply-To: <20230522031217.956464-1-zhaotianrui@loongson.cn> References: <20230522031217.956464-1-zhaotianrui@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Add KVM LoongArch support \| expand [v11,00/31] Add KVM LoongArch support [v11,01/31] LoongArch: KVM: Add kvm related header files [v11,02/31] LoongArch: KVM: Implement kvm module related interface [v11,03/31] LoongArch: KVM: Implement kvm hardware enable, disable interface [v11,04/31] LoongArch: KVM: Implement VM related functions [v11,05/31] LoongArch: KVM: Add vcpu related header files [v11,06/31] LoongArch: KVM: Implement vcpu create and destroy interface [v11,07/31] LoongArch: KVM: Implement vcpu run interface [v11,08/31] LoongArch: KVM: Implement vcpu handle exit interface [v11,09/31] LoongArch: KVM: Implement vcpu get, vcpu set registers [v11,10/31] LoongArch: KVM: Implement vcpu ENABLE_CAP ioctl interface [v11,11/31] LoongArch: KVM: Implement fpu related operations for vcpu [v11,12/31] LoongArch: KVM: Implement vcpu interrupt operations [v11,13/31] LoongArch: KVM: Implement misc vcpu related interfaces [v11,14/31] LoongArch: KVM: Implement vcpu load and vcpu put operations [v11,15/31] LoongArch: KVM: Implement vcpu status description [v11,16/31] LoongArch: KVM: Implement update VM id function [v11,17/31] LoongArch: KVM: Implement virtual machine tlb operations [v11,18/31] LoongArch: KVM: Implement vcpu timer operations [v11,19/31] LoongArch: KVM: Implement kvm mmu operations [v11,20/31] LoongArch: KVM: Implement handle csr excption [v11,21/31] LoongArch: KVM: Implement handle iocsr exception [v11,22/31] LoongArch: KVM: Implement handle idle exception [v11,23/31] LoongArch: KVM: Implement handle gspr exception [v11,24/31] LoongArch: KVM: Implement handle mmio exception [v11,25/31] LoongArch: KVM: Implement handle fpu exception [v11,26/31] LoongArch: KVM: Implement kvm exception vector [v11,27/31] LoongArch: KVM: Implement vcpu world switch [v11,28/31] LoongArch: KVM: Implement probe virtualization when LoongArch cpu init [v11,29/31] LoongArch: KVM: Enable kvm config and add the makefile [v11,30/31] LoongArch: KVM: Supplement kvm document about LoongArch-specific part [v11,31/31] LoongArch: KVM: Add maintainers for LoongArch KVM

diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c index 4bdb203fc66e..0c055f2046eb 100644 --- a/arch/loongarch/kernel/asm-offsets.c +++ b/arch/loongarch/kernel/asm-offsets.c @@ -9,6 +9,7 @@ #include <linux/mm.h> #include <linux/kbuild.h> #include <linux/suspend.h> +#include <linux/kvm_host.h> #include <asm/cpu-info.h> #include <asm/ptrace.h> #include <asm/processor.h> @@ -272,3 +273,34 @@ void output_pbe_defines(void) BLANK(); } #endif + +static void __used output_kvm_defines(void) +{ + COMMENT(" KVM/LOONGARCH Specific offsets. "); + + OFFSET(VCPU_FCSR0, kvm_vcpu_arch, fpu.fcsr); + OFFSET(VCPU_FCC, kvm_vcpu_arch, fpu.fcc); + BLANK(); + + OFFSET(KVM_VCPU_ARCH, kvm_vcpu, arch); + OFFSET(KVM_VCPU_KVM, kvm_vcpu, kvm); + OFFSET(KVM_VCPU_RUN, kvm_vcpu, run); + BLANK(); + + OFFSET(KVM_ARCH_HSTACK, kvm_vcpu_arch, host_stack); + OFFSET(KVM_ARCH_HGP, kvm_vcpu_arch, host_gp); + OFFSET(KVM_ARCH_HANDLE_EXIT, kvm_vcpu_arch, handle_exit); + OFFSET(KVM_ARCH_HPGD, kvm_vcpu_arch, host_pgd); + OFFSET(KVM_ARCH_GEENTRY, kvm_vcpu_arch, guest_eentry); + OFFSET(KVM_ARCH_GPC, kvm_vcpu_arch, pc); + OFFSET(KVM_ARCH_GGPR, kvm_vcpu_arch, gprs); + OFFSET(KVM_ARCH_HESTAT, kvm_vcpu_arch, host_estat); + OFFSET(KVM_ARCH_HBADV, kvm_vcpu_arch, badv); + OFFSET(KVM_ARCH_HBADI, kvm_vcpu_arch, badi); + OFFSET(KVM_ARCH_HECFG, kvm_vcpu_arch, host_ecfg); + OFFSET(KVM_ARCH_HEENTRY, kvm_vcpu_arch, host_eentry); + OFFSET(KVM_ARCH_HPERCPU, kvm_vcpu_arch, host_percpu); + + OFFSET(KVM_GPGD, kvm, arch.gpa_mm.pgd); + BLANK(); +} diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S new file mode 100644 index 000000000000..1f36ae84ccc3 --- /dev/null +++ b/arch/loongarch/kvm/switch.S @@ -0,0 +1,301 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited + */ + +#include <linux/linkage.h> +#include <asm/stackframe.h> +#include <asm/asm.h> +#include <asm/asmmacro.h> +#include <asm/regdef.h> +#include <asm/loongarch.h> +#include <asm/export.h> + +#define PT_GPR_OFFSET(x) (PT_R0 + 8*x) + .text + +.macro kvm_save_host_gpr base + .irp n,1,2,3,22,23,24,25,26,27,28,29,30,31 + st.d $r\n, \base, PT_GPR_OFFSET(\n) + .endr +.endm + +.macro kvm_restore_host_gpr base + .irp n,1,2,3,22,23,24,25,26,27,28,29,30,31 + ld.d $r\n, \base, PT_GPR_OFFSET(\n) + .endr +.endm + +/* + * prepare switch to guest, save host reg and restore guest reg. + * a2: kvm_vcpu_arch, don't touch it until 'ertn' + * t0, t1: temp register + */ +.macro kvm_switch_to_guest + /* set host excfg.VS=0, all exceptions share one exception entry */ + csrrd t0, LOONGARCH_CSR_ECFG + bstrins.w t0, zero, CSR_ECFG_VS_SHIFT_END, CSR_ECFG_VS_SHIFT + csrwr t0, LOONGARCH_CSR_ECFG + + /* Load up the new EENTRY */ + ld.d t0, a2, KVM_ARCH_GEENTRY + csrwr t0, LOONGARCH_CSR_EENTRY + + /* Set Guest ERA */ + ld.d t0, a2, KVM_ARCH_GPC + csrwr t0, LOONGARCH_CSR_ERA + + /* Save host PGDL */ + csrrd t0, LOONGARCH_CSR_PGDL + st.d t0, a2, KVM_ARCH_HPGD + + /* Switch to kvm */ + ld.d t1, a2, KVM_VCPU_KVM - KVM_VCPU_ARCH + + /* Load guest PGDL */ + lu12i.w t0, KVM_GPGD + srli.w t0, t0, 12 + ldx.d t0, t1, t0 + csrwr t0, LOONGARCH_CSR_PGDL + + /* Mix GID and RID */ + csrrd t1, LOONGARCH_CSR_GSTAT + bstrpick.w t1, t1, CSR_GSTAT_GID_SHIFT_END, CSR_GSTAT_GID_SHIFT + csrrd t0, LOONGARCH_CSR_GTLBC + bstrins.w t0, t1, CSR_GTLBC_TGID_SHIFT_END, CSR_GTLBC_TGID_SHIFT + csrwr t0, LOONGARCH_CSR_GTLBC + + /* + * Switch to guest: + * GSTAT.PGM = 1, ERRCTL.ISERR = 0, TLBRPRMD.ISTLBR = 0 + * ertn + */ + + /* + * Enable intr in root mode with future ertn so that host interrupt + * can be responsed during VM runs + * guest crmd comes from separate gcsr_CRMD register + */ + ori t0, zero, CSR_PRMD_PIE + csrxchg t0, t0, LOONGARCH_CSR_PRMD + + /* Set PVM bit to setup ertn to guest context */ + ori t0, zero, CSR_GSTAT_PVM + csrxchg t0, t0, LOONGARCH_CSR_GSTAT + + /* Load Guest gprs */ + ld.d ra, a2, (KVM_ARCH_GGPR + 8 * REG_RA) + ld.d tp, a2, (KVM_ARCH_GGPR + 8 * REG_TP) + ld.d sp, a2, (KVM_ARCH_GGPR + 8 * REG_SP) + ld.d a0, a2, (KVM_ARCH_GGPR + 8 * REG_A0) + ld.d a1, a2, (KVM_ARCH_GGPR + 8 * REG_A1) + ld.d a3, a2, (KVM_ARCH_GGPR + 8 * REG_A3) + ld.d a4, a2, (KVM_ARCH_GGPR + 8 * REG_A4) + ld.d a5, a2, (KVM_ARCH_GGPR + 8 * REG_A5) + ld.d a6, a2, (KVM_ARCH_GGPR + 8 * REG_A6) + ld.d a7, a2, (KVM_ARCH_GGPR + 8 * REG_A7) + ld.d t0, a2, (KVM_ARCH_GGPR + 8 * REG_T0) + ld.d t1, a2, (KVM_ARCH_GGPR + 8 * REG_T1) + ld.d t2, a2, (KVM_ARCH_GGPR + 8 * REG_T2) + ld.d t3, a2, (KVM_ARCH_GGPR + 8 * REG_T3) + ld.d t4, a2, (KVM_ARCH_GGPR + 8 * REG_T4) + ld.d t5, a2, (KVM_ARCH_GGPR + 8 * REG_T5) + ld.d t6, a2, (KVM_ARCH_GGPR + 8 * REG_T6) + ld.d t7, a2, (KVM_ARCH_GGPR + 8 * REG_T7) + ld.d t8, a2, (KVM_ARCH_GGPR + 8 * REG_T8) + ld.d u0, a2, (KVM_ARCH_GGPR + 8 * REG_U0) + ld.d fp, a2, (KVM_ARCH_GGPR + 8 * REG_FP) + ld.d s0, a2, (KVM_ARCH_GGPR + 8 * REG_S0) + ld.d s1, a2, (KVM_ARCH_GGPR + 8 * REG_S1) + ld.d s2, a2, (KVM_ARCH_GGPR + 8 * REG_S2) + ld.d s3, a2, (KVM_ARCH_GGPR + 8 * REG_S3) + ld.d s4, a2, (KVM_ARCH_GGPR + 8 * REG_S4) + ld.d s5, a2, (KVM_ARCH_GGPR + 8 * REG_S5) + ld.d s6, a2, (KVM_ARCH_GGPR + 8 * REG_S6) + ld.d s7, a2, (KVM_ARCH_GGPR + 8 * REG_S7) + ld.d s8, a2, (KVM_ARCH_GGPR + 8 * REG_S8) + /* Load KVM_ARCH register */ + ld.d a2, a2, (KVM_ARCH_GGPR + 8 * REG_A2) + + ertn +.endm + + /* + * exception entry for general exception from guest mode + * - IRQ is disabled + * - kernel privilege in root mode + * - page mode keep unchanged from previous prmd in root mode + * - Fixme: tlb exception cannot happen since registers relative with TLB + * - is still in guest mode, such as pgd table/vmid registers etc, + * - will fix with hw page walk enabled in future + * load kvm_vcpu from reserved CSR KVM_VCPU_KS, and save a2 to KVM_TEMP_KS + */ + .section .text + .cfi_sections .debug_frame +SYM_CODE_START(kvm_vector_entry) + csrwr a2, KVM_TEMP_KS + csrrd a2, KVM_VCPU_KS + addi.d a2, a2, KVM_VCPU_ARCH + + /* After save gprs, free to use any gpr */ + st.d ra, a2, (KVM_ARCH_GGPR + 8 * REG_RA) + st.d tp, a2, (KVM_ARCH_GGPR + 8 * REG_TP) + st.d sp, a2, (KVM_ARCH_GGPR + 8 * REG_SP) + st.d a0, a2, (KVM_ARCH_GGPR + 8 * REG_A0) + st.d a1, a2, (KVM_ARCH_GGPR + 8 * REG_A1) + st.d a3, a2, (KVM_ARCH_GGPR + 8 * REG_A3) + st.d a4, a2, (KVM_ARCH_GGPR + 8 * REG_A4) + st.d a5, a2, (KVM_ARCH_GGPR + 8 * REG_A5) + st.d a6, a2, (KVM_ARCH_GGPR + 8 * REG_A6) + st.d a7, a2, (KVM_ARCH_GGPR + 8 * REG_A7) + st.d t0, a2, (KVM_ARCH_GGPR + 8 * REG_T0) + st.d t1, a2, (KVM_ARCH_GGPR + 8 * REG_T1) + st.d t2, a2, (KVM_ARCH_GGPR + 8 * REG_T2) + st.d t3, a2, (KVM_ARCH_GGPR + 8 * REG_T3) + st.d t4, a2, (KVM_ARCH_GGPR + 8 * REG_T4) + st.d t5, a2, (KVM_ARCH_GGPR + 8 * REG_T5) + st.d t6, a2, (KVM_ARCH_GGPR + 8 * REG_T6) + st.d t7, a2, (KVM_ARCH_GGPR + 8 * REG_T7) + st.d t8, a2, (KVM_ARCH_GGPR + 8 * REG_T8) + st.d u0, a2, (KVM_ARCH_GGPR + 8 * REG_U0) + st.d fp, a2, (KVM_ARCH_GGPR + 8 * REG_FP) + st.d s0, a2, (KVM_ARCH_GGPR + 8 * REG_S0) + st.d s1, a2, (KVM_ARCH_GGPR + 8 * REG_S1) + st.d s2, a2, (KVM_ARCH_GGPR + 8 * REG_S2) + st.d s3, a2, (KVM_ARCH_GGPR + 8 * REG_S3) + st.d s4, a2, (KVM_ARCH_GGPR + 8 * REG_S4) + st.d s5, a2, (KVM_ARCH_GGPR + 8 * REG_S5) + st.d s6, a2, (KVM_ARCH_GGPR + 8 * REG_S6) + st.d s7, a2, (KVM_ARCH_GGPR + 8 * REG_S7) + st.d s8, a2, (KVM_ARCH_GGPR + 8 * REG_S8) + /* Save guest a2 */ + csrrd t0, KVM_TEMP_KS + st.d t0, a2, (KVM_ARCH_GGPR + 8 * REG_A2) + + /* a2: kvm_vcpu_arch, a1 is free to use */ + csrrd s1, KVM_VCPU_KS + ld.d s0, s1, KVM_VCPU_RUN + + csrrd t0, LOONGARCH_CSR_ESTAT + st.d t0, a2, KVM_ARCH_HESTAT + csrrd t0, LOONGARCH_CSR_ERA + st.d t0, a2, KVM_ARCH_GPC + csrrd t0, LOONGARCH_CSR_BADV + st.d t0, a2, KVM_ARCH_HBADV + csrrd t0, LOONGARCH_CSR_BADI + st.d t0, a2, KVM_ARCH_HBADI + + /* Restore host excfg.VS */ + csrrd t0, LOONGARCH_CSR_ECFG + ld.d t1, a2, KVM_ARCH_HECFG + or t0, t0, t1 + csrwr t0, LOONGARCH_CSR_ECFG + + /* Restore host eentry */ + ld.d t0, a2, KVM_ARCH_HEENTRY + csrwr t0, LOONGARCH_CSR_EENTRY + + /* restore host pgd table */ + ld.d t0, a2, KVM_ARCH_HPGD + csrwr t0, LOONGARCH_CSR_PGDL + + /* + * Disable PGM bit to enter root mode by default with next ertn + */ + ori t0, zero, CSR_GSTAT_PVM + csrxchg zero, t0, LOONGARCH_CSR_GSTAT + /* + * Clear GTLBC.TGID field + * 0: for root tlb update in future tlb instr + * others: for guest tlb update like gpa to hpa in future tlb instr + */ + csrrd t0, LOONGARCH_CSR_GTLBC + bstrins.w t0, zero, CSR_GTLBC_TGID_SHIFT_END, CSR_GTLBC_TGID_SHIFT + csrwr t0, LOONGARCH_CSR_GTLBC + ld.d tp, a2, KVM_ARCH_HGP + ld.d sp, a2, KVM_ARCH_HSTACK + /* restore per cpu register */ + ld.d u0, a2, KVM_ARCH_HPERCPU + addi.d sp, sp, -PT_SIZE + + /* Prepare handle exception */ + or a0, s0, zero + or a1, s1, zero + ld.d t8, a2, KVM_ARCH_HANDLE_EXIT + jirl ra,t8, 0 + + or a2, s1, zero + addi.d a2, a2, KVM_VCPU_ARCH + + /* resume host when ret <= 0 */ + bge zero, a0, ret_to_host + + /* + * return to guest + * save per cpu register again, maybe switched to another cpu + */ + st.d u0, a2, KVM_ARCH_HPERCPU + + /* Save kvm_vcpu to kscratch */ + csrwr s1, KVM_VCPU_KS + kvm_switch_to_guest + +ret_to_host: + ld.d a2, a2, KVM_ARCH_HSTACK + addi.d a2, a2, -PT_SIZE + kvm_restore_host_gpr a2 + jirl zero, ra, 0 +SYM_CODE_END(kvm_vector_entry) +kvm_vector_entry_end: + +/* + * int kvm_enter_guest(struct kvm_run *run, struct kvm_vcpu *vcpu) + * + * @register_param: + * a0: kvm_run* run + * a1: kvm_vcpu* vcpu + */ +SYM_FUNC_START(kvm_enter_guest) + /* allocate space in stack bottom */ + addi.d a2, sp, -PT_SIZE + /* save host gprs */ + kvm_save_host_gpr a2 + + /* save host crmd,prmd csr to stack */ + csrrd a3, LOONGARCH_CSR_CRMD + st.d a3, a2, PT_CRMD + csrrd a3, LOONGARCH_CSR_PRMD + st.d a3, a2, PT_PRMD + + addi.d a2, a1, KVM_VCPU_ARCH + st.d sp, a2, KVM_ARCH_HSTACK + st.d tp, a2, KVM_ARCH_HGP + /* Save per cpu register */ + st.d u0, a2, KVM_ARCH_HPERCPU + + /* Save kvm_vcpu to kscratch */ + csrwr a1, KVM_VCPU_KS + kvm_switch_to_guest +SYM_FUNC_END(kvm_enter_guest) +kvm_enter_guest_end: + + .section ".rodata" +SYM_DATA(kvm_vector_size, + .quad kvm_vector_entry_end - kvm_vector_entry) +SYM_DATA(kvm_enter_guest_size, + .quad kvm_enter_guest_end - kvm_enter_guest) + + +SYM_FUNC_START(kvm_save_fpu) + fpu_save_csr a0 t1 + fpu_save_double a0 t1 + fpu_save_cc a0 t1 t2 + jirl zero, ra, 0 +SYM_FUNC_END(kvm_save_fpu) + +SYM_FUNC_START(kvm_restore_fpu) + fpu_restore_double a0 t1 + fpu_restore_csr a0 t1 + fpu_restore_cc a0 t1 t2 + jirl zero, ra, 0 +SYM_FUNC_END(kvm_restore_fpu)

[v11,27/31] LoongArch: KVM: Implement vcpu world switch

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