mirror of
https://github.com/revyos/thead-kernel.git
synced 2026-07-20 07:08:05 +02:00
136 lines
3.1 KiB
C
136 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bitops.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/kvm_host.h>
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#include <asm/csr.h>
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/**
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* kvm_riscv_vcpu_mmio_return -- Handle MMIO loads after user space emulation
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* or in-kernel IO emulation
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*
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* @vcpu: The VCPU pointer
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* @run: The VCPU run struct containing the mmio data
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*/
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int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
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{
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struct kvm *kvm = vcpu->kvm;
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struct khv_io *io_switch = kvm->arch.io_switch;
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int len;
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if (run->mmio.is_write)
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goto out;
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if (io_switch->status & BIT(7))
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while(1)
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printk_once(KERN_INFO "Can't be mmio write here\n");
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len = 1 << ((io_switch->status >> 8) & 0xf);
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switch (len) {
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case 1:
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*((u8 *)&io_switch->value) = *((u8 *)run->mmio.data);
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break;
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case 2:
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*((u16 *)&io_switch->value) = *((u16 *)run->mmio.data);
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break;
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case 4:
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*((u32 *)&io_switch->value) = *((u32 *)run->mmio.data);
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break;
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case 8:
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*((u64 *)&io_switch->value) = *((u64 *)run->mmio.data);
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break;
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default:
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return -EOPNOTSUPP;
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};
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out:
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if ((run->mmio.phys_addr & 0xff) != 0x50 ) { // skip VIRTIO_MMIO_QUEUE_NOTIFY
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// READY
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writeb(2, (void __iomem *)&io_switch->status);
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while (readb((void __iomem *)&io_switch->status) != 3)
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cpu_relax();
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}
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writel(0, (void __iomem *)&io_switch->status);
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return 0;
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}
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/*
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* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
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* proper exit to userspace.
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*/
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int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
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struct kvm_cpu_trap *trap)
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{
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int ret;
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struct kvm *kvm = vcpu->kvm;
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struct khv_io *io_switch = kvm->arch.io_switch;
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int len;
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ret = -EFAULT;
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if (((io_switch->status >> 16) & 0xff) == 0x5a) {
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run->exit_reason = KVM_EXIT_SHUTDOWN;
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io_switch->status = 0;
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return 0;
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}
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run->exit_reason = KVM_EXIT_UNKNOWN;
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len = 1 << ((io_switch->status >> 8) & 0xf);
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/* Update MMIO details in kvm_run struct */
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run->mmio.phys_addr = io_switch->addr;
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run->mmio.len = len;
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if (io_switch->status & BIT(7))
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run->mmio.is_write = 1;
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else {
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run->mmio.is_write = 0;
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goto out;
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}
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/* Copy data to kvm_run instance */
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switch (len) {
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case 1:
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*((u8 *)run->mmio.data) = *((u8 *)&io_switch->value);
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break;
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case 2:
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*((u16 *)run->mmio.data) = *((u16 *)&io_switch->value);
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break;
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case 4:
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*((u32 *)run->mmio.data) = *((u32 *)&io_switch->value);
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break;
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case 8:
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*((u64 *)run->mmio.data) = *((u64 *)&io_switch->value);
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break;
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default:
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pr_info("%s, %llx, len: %d.\n", __func__, io_switch->status, len);
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return -EOPNOTSUPP;
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};
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pr_debug("mmio: 0x%llx 0x%x %d %d\n",
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run->mmio.phys_addr, *((u32 *)run->mmio.data),
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len, run->mmio.is_write);
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out:
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/* Try to handle MMIO access in the kernel */
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if (!kvm_io_bus_write(vcpu, KVM_MMIO_BUS,
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io_switch->addr, len, run->mmio.data)) {
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/* Successfully handled MMIO access in the kernel so resume */
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vcpu->stat.mmio_exit_kernel++;
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kvm_riscv_vcpu_mmio_return(vcpu, run);
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return 1;
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}
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/* Exit to userspace for MMIO emulation */
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vcpu->stat.mmio_exit_user++;
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run->exit_reason = KVM_EXIT_MMIO;
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return 0;
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}
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