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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/arm64/kvm/hyp/sysreg-sr.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/sysreg-sr.c')
-rw-r--r--arch/arm64/kvm/hyp/sysreg-sr.c306
1 files changed, 306 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
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+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -0,0 +1,306 @@
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * 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/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kprobes.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+
+/*
+ * Non-VHE: Both host and guest must save everything.
+ *
+ * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and pstate,
+ * which are handled as part of the el2 return state) on every switch.
+ * tpidr_el0 and tpidrro_el0 only need to be switched when going
+ * to host userspace or a different VCPU. EL1 registers only need to be
+ * switched when potentially going to run a different VCPU. The latter two
+ * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put.
+ */
+
+static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
+{
+ ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
+
+ /*
+ * The host arm64 Linux uses sp_el0 to point to 'current' and it must
+ * therefore be saved/restored on every entry/exit to/from the guest.
+ */
+ ctxt->gp_regs.regs.sp = read_sysreg(sp_el0);
+}
+
+static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
+{
+ ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
+ ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
+}
+
+static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
+{
+ ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2);
+ ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
+ ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr);
+ ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
+ ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr);
+ ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0);
+ ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1);
+ ctxt->sys_regs[TCR_EL1] = read_sysreg_el1(tcr);
+ ctxt->sys_regs[ESR_EL1] = read_sysreg_el1(esr);
+ ctxt->sys_regs[AFSR0_EL1] = read_sysreg_el1(afsr0);
+ ctxt->sys_regs[AFSR1_EL1] = read_sysreg_el1(afsr1);
+ ctxt->sys_regs[FAR_EL1] = read_sysreg_el1(far);
+ ctxt->sys_regs[MAIR_EL1] = read_sysreg_el1(mair);
+ ctxt->sys_regs[VBAR_EL1] = read_sysreg_el1(vbar);
+ ctxt->sys_regs[CONTEXTIDR_EL1] = read_sysreg_el1(contextidr);
+ ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
+ ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
+ ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
+ ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
+
+ ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
+ ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
+ ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
+}
+
+static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
+{
+ ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
+ ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
+
+ if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
+ ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);
+}
+
+void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_el1_state(ctxt);
+ __sysreg_save_common_state(ctxt);
+ __sysreg_save_user_state(ctxt);
+ __sysreg_save_el2_return_state(ctxt);
+}
+
+void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_common_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_save_host_state_vhe);
+
+void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_common_state(ctxt);
+ __sysreg_save_el2_return_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
+
+static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
+{
+ write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
+
+ /*
+ * The host arm64 Linux uses sp_el0 to point to 'current' and it must
+ * therefore be saved/restored on every entry/exit to/from the guest.
+ */
+ write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
+}
+
+static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
+{
+ write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
+ write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
+}
+
+static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
+{
+ write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
+ write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
+ write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr);
+ write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
+ write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr);
+ write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], ttbr0);
+ write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], ttbr1);
+ write_sysreg_el1(ctxt->sys_regs[TCR_EL1], tcr);
+ write_sysreg_el1(ctxt->sys_regs[ESR_EL1], esr);
+ write_sysreg_el1(ctxt->sys_regs[AFSR0_EL1], afsr0);
+ write_sysreg_el1(ctxt->sys_regs[AFSR1_EL1], afsr1);
+ write_sysreg_el1(ctxt->sys_regs[FAR_EL1], far);
+ write_sysreg_el1(ctxt->sys_regs[MAIR_EL1], mair);
+ write_sysreg_el1(ctxt->sys_regs[VBAR_EL1], vbar);
+ write_sysreg_el1(ctxt->sys_regs[CONTEXTIDR_EL1],contextidr);
+ write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
+ write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
+ write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
+ write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
+
+ write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
+ write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
+ write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
+}
+
+static void __hyp_text
+__sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
+{
+ write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
+ write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
+
+ if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
+ write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);
+}
+
+void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_el1_state(ctxt);
+ __sysreg_restore_common_state(ctxt);
+ __sysreg_restore_user_state(ctxt);
+ __sysreg_restore_el2_return_state(ctxt);
+}
+
+void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_common_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe);
+
+void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_common_state(ctxt);
+ __sysreg_restore_el2_return_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);
+
+void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
+{
+ u64 *spsr, *sysreg;
+
+ if (!vcpu_el1_is_32bit(vcpu))
+ return;
+
+ spsr = vcpu->arch.ctxt.gp_regs.spsr;
+ sysreg = vcpu->arch.ctxt.sys_regs;
+
+ spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
+ spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
+ spsr[KVM_SPSR_IRQ] = read_sysreg(spsr_irq);
+ spsr[KVM_SPSR_FIQ] = read_sysreg(spsr_fiq);
+
+ sysreg[DACR32_EL2] = read_sysreg(dacr32_el2);
+ sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2);
+
+ if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
+ sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2);
+}
+
+void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
+{
+ u64 *spsr, *sysreg;
+
+ if (!vcpu_el1_is_32bit(vcpu))
+ return;
+
+ spsr = vcpu->arch.ctxt.gp_regs.spsr;
+ sysreg = vcpu->arch.ctxt.sys_regs;
+
+ write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
+ write_sysreg(spsr[KVM_SPSR_UND], spsr_und);
+ write_sysreg(spsr[KVM_SPSR_IRQ], spsr_irq);
+ write_sysreg(spsr[KVM_SPSR_FIQ], spsr_fiq);
+
+ write_sysreg(sysreg[DACR32_EL2], dacr32_el2);
+ write_sysreg(sysreg[IFSR32_EL2], ifsr32_el2);
+
+ if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
+ write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2);
+}
+
+/**
+ * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU
+ *
+ * @vcpu: The VCPU pointer
+ *
+ * Load system registers that do not affect the host's execution, for
+ * example EL1 system registers on a VHE system where the host kernel
+ * runs at EL2. This function is called from KVM's vcpu_load() function
+ * and loading system register state early avoids having to load them on
+ * every entry to the VM.
+ */
+void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
+ struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+
+ if (!has_vhe())
+ return;
+
+ __sysreg_save_user_state(host_ctxt);
+
+ /*
+ * Load guest EL1 and user state
+ *
+ * We must restore the 32-bit state before the sysregs, thanks
+ * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
+ */
+ __sysreg32_restore_state(vcpu);
+ __sysreg_restore_user_state(guest_ctxt);
+ __sysreg_restore_el1_state(guest_ctxt);
+
+ vcpu->arch.sysregs_loaded_on_cpu = true;
+
+ activate_traps_vhe_load(vcpu);
+}
+
+/**
+ * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU
+ *
+ * @vcpu: The VCPU pointer
+ *
+ * Save guest system registers that do not affect the host's execution, for
+ * example EL1 system registers on a VHE system where the host kernel
+ * runs at EL2. This function is called from KVM's vcpu_put() function
+ * and deferring saving system register state until we're no longer running the
+ * VCPU avoids having to save them on every exit from the VM.
+ */
+void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
+ struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+
+ if (!has_vhe())
+ return;
+
+ deactivate_traps_vhe_put();
+
+ __sysreg_save_el1_state(guest_ctxt);
+ __sysreg_save_user_state(guest_ctxt);
+ __sysreg32_save_state(vcpu);
+
+ /* Restore host user state */
+ __sysreg_restore_user_state(host_ctxt);
+
+ vcpu->arch.sysregs_loaded_on_cpu = false;
+}
+
+void __hyp_text __kvm_enable_ssbs(void)
+{
+ u64 tmp;
+
+ asm volatile(
+ "mrs %0, sctlr_el2\n"
+ "orr %0, %0, %1\n"
+ "msr sctlr_el2, %0"
+ : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));
+}