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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm64/kvm/hyp/vhe/sysreg-sr.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/vhe/sysreg-sr.c')
-rw-r--r--arch/arm64/kvm/hyp/vhe/sysreg-sr.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
new file mode 100644
index 000000000..7b44f6b3b
--- /dev/null
+++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <hyp/sysreg-sr.h>
+
+#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>
+
+/*
+ * 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 (sp_el0 is being dealt with in the assembly code).
+ * 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.
+ */
+
+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);
+
+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);
+
+/**
+ * kvm_vcpu_load_sysregs_vhe - 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_vhe(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+ struct kvm_cpu_context *host_ctxt;
+
+ host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+ __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_set_flag(vcpu, SYSREGS_ON_CPU);
+
+ activate_traps_vhe_load(vcpu);
+}
+
+/**
+ * kvm_vcpu_put_sysregs_vhe - 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_vhe(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+ struct kvm_cpu_context *host_ctxt;
+
+ host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+ deactivate_traps_vhe_put(vcpu);
+
+ __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_clear_flag(vcpu, SYSREGS_ON_CPU);
+}