From: "Pranavkumar Sawargaonkar" pranavkumar@linaro.org

This patch is a counterpart implementation of virtio-mmio console early printk support in kvmtool for a rfc i posted today on kvm-arm i.e. ([RFC] arm64: Early printk support for virtio-mmio console devices) This is initial reference version (might not be very clean). This allows guest to print early printk on virtio-mmio console.

Signed-off-by: Anup Patel anup.patel@linaro.org --- tools/kvm/include/kvm/virtio-console.h | 5 +++++ tools/kvm/virtio/console.c | 30 +++++++++++++++++++++++++++++- tools/kvm/virtio/mmio.c | 24 +++++++++++++++++++----- 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/tools/kvm/include/kvm/virtio-console.h b/tools/kvm/include/kvm/virtio-console.h index 8980920..063c8bb 100644 --- a/tools/kvm/include/kvm/virtio-console.h +++ b/tools/kvm/include/kvm/virtio-console.h @@ -1,10 +1,15 @@ #ifndef KVM__CONSOLE_VIRTIO_H #define KVM__CONSOLE_VIRTIO_H

+#include <linux/types.h> + struct kvm;

int virtio_console__init(struct kvm *kvm); void virtio_console__inject_interrupt(struct kvm *kvm); int virtio_console__exit(struct kvm *kvm);

+void console_write_config(struct kvm *kvm, void *dev, u64 addr, u32 i, u8 *data); +void console_read_config(struct kvm *kvm, void *dev, u64 addr, u32 i, u8 *data); + #endif /* KVM__CONSOLE_VIRTIO_H */ diff --git a/tools/kvm/virtio/console.c b/tools/kvm/virtio/console.c index b18d3a9..47ae890 100644 --- a/tools/kvm/virtio/console.c +++ b/tools/kvm/virtio/console.c @@ -118,9 +118,37 @@ static u8 *get_config(struct kvm *kvm, void *dev) return ((u8 *)(&cdev->config)); }

+void console_write_config(struct kvm *kvm, void *dev, u64 addr, u32 i, u8 *data) +{ + struct con_dev *cdev = dev; + u8 *p; + + if (addr != offsetof(struct virtio_console_config, early_rw)) { + p = ((u8 *)(&cdev->config)); + p[addr + i] = *(u8 *)data + i; + + } else { + /* early_rw write */ + term_putc((char *) (data + i), 1, 0); + } +} + +void console_read_config(struct kvm *kvm, void *dev, u64 addr, u32 i, u8 *data) +{ + struct con_dev *cdev = dev; + u8 *p; + + if (addr != offsetof(struct virtio_console_config, early_rw)) { + p = ((u8 *)(&cdev->config)); + data[i] = p[addr + i]; + } else { + /* TBD: implement early_rw read with the help of term_getc */ + } +} + static u32 get_host_features(struct kvm *kvm, void *dev) { - return 0; + return (1 << VIRTIO_CONSOLE_F_EARLY_WRITE); }

static void set_guest_features(struct kvm *kvm, void *dev, u32 features) diff --git a/tools/kvm/virtio/mmio.c b/tools/kvm/virtio/mmio.c index bd30f37..6b116e9 100644 --- a/tools/kvm/virtio/mmio.c +++ b/tools/kvm/virtio/mmio.c @@ -3,9 +3,11 @@ #include "kvm/ioeventfd.h" #include "kvm/ioport.h" #include "kvm/virtio.h" +#include "kvm/virtio-console.h" #include "kvm/kvm.h" #include "kvm/irq.h"

+#include <linux/virtio_ids.h> #include <linux/virtio_mmio.h> #include <string.h>

@@ -94,12 +96,24 @@ static void virtio_mmio_device_specific(u64 addr, u8 *data, u32 len, u32 i;

for (i = 0; i < len; i++) { - if (is_write) - vdev->ops->get_config(vmmio->kvm, vmmio->dev)[addr + i] = - *(u8 *)data + i; - else - data[i] = vdev->ops->get_config(vmmio->kvm, + if (is_write) { + if (vmmio->hdr.device_id == VIRTIO_ID_CONSOLE) { + console_write_config(vmmio->kvm, vmmio->dev, + addr, i, data); + } else { + vdev->ops->get_config(vmmio->kvm, + vmmio->dev)[addr + i] = + *(u8 *)data + i; + } + } else { + if (vmmio->hdr.device_id == VIRTIO_ID_CONSOLE) { + console_read_config(vmmio->kvm, vmmio->dev, + addr, i, data); + } else { + data[i] = vdev->ops->get_config(vmmio->kvm, vmmio->dev)[addr + i]; + } + } } }