Introduce vpl011 support to guests started from Xen: it provides a
simple way to print output from a guest, as most guests come with a
pl011 driver. It is also able to provide a working console with
interrupt support.
The UART exposed to the guest is a SBSA compatible UART and not a PL011.
SBSA UART is a subset of PL011 r1p5. A full PL011 implementation in Xen
would just be too difficult, so guests may require some drivers changes.
Enable vpl011 conditionally if the user requested it.
Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
---
Changes in v4:
- move rename set_interrupt_ppi and making set_interrupt_ppi generic to
a separate patch
- properly name the vpl011 device node name
- code style
- use #define for addrcells and sizecells
Changes in v3:
- use bool
- retain BUG_ON(irq < 16)
- add vpl011 bool to kinfo
- return error of vpl011 is required but CONFIG_SBSA_VUART_CONSOLE is
missing
Changes in v2:
- code style fixes
- make set_interrupt_ppi generic
- rename set_interrupt_ppi to set_interrupt
- only make the vpl011 node if the option was enabled
---
xen/arch/arm/domain_build.c | 61 +++++++++++++++++++++++++++++++++++++++++++++
xen/arch/arm/kernel.h | 3 +++
2 files changed, 64 insertions(+)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 760ebf8..049ab84 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1605,6 +1605,54 @@ static int __init make_timer_domU_node(const struct
domain *d, void *fdt)
return res;
}
+#ifdef CONFIG_SBSA_VUART_CONSOLE
+static int __init make_vpl011_uart_node(const struct domain *d, void *fdt)
+{
+ int res;
+ gic_interrupt_t intr;
+ __be32 reg[GUEST_ROOT_ADDRESS_CELLS + GUEST_ROOT_SIZE_CELLS];
+ __be32 *cells;
+
+ res = fdt_begin_node(fdt, "sbsa-uart@"__stringify(GUEST_PL011_BASE));
+ if ( res )
+ return res;
+
+ res = fdt_property_string(fdt, "compatible", "arm,sbsa-uart");
+ if ( res )
+ return res;
+
+ cells = ®[0];
+ dt_child_set_range(&cells, GUEST_ROOT_ADDRESS_CELLS,
+ GUEST_ROOT_SIZE_CELLS, GUEST_PL011_BASE,
+ GUEST_PL011_SIZE);
+ if ( res )
+ return res;
+ res = fdt_property(fdt, "reg", reg, sizeof(reg));
+ if ( res )
+ return res;
+
+ set_interrupt(intr, GUEST_VPL011_SPI, 0xf, DT_IRQ_TYPE_LEVEL_HIGH);
+
+ res = fdt_property(fdt, "interrupts", intr, sizeof (intr));
+ if ( res )
+ return res;
+
+ res = fdt_property_cell(fdt, "interrupt-parent",
+ GUEST_PHANDLE_GIC);
+ if ( res )
+ return res;
+
+ /* Use a default baud rate of 115200. */
+ fdt_property_u32(fdt, "current-speed", 115200);
+
+ res = fdt_end_node(fdt);
+ if ( res )
+ return res;
+
+ return 0;
+}
+#endif
+
/*
* The max size for DT is 2MB. However, the generated DT is small, 4KB
* are enough for now, but we might have to increase it in the future.
@@ -1666,6 +1714,16 @@ static int __init prepare_dtb_domU(struct domain *d,
struct kernel_info *kinfo)
if ( ret )
goto err;
+ if ( kinfo->vpl011 )
+ {
+ ret = -EINVAL;
+#ifdef CONFIG_SBSA_VUART_CONSOLE
+ ret = make_vpl011_uart_node(d, kinfo->fdt);
+#endif
+ if ( ret )
+ goto err;
+ }
+
ret = fdt_end_node(kinfo->fdt);
if ( ret < 0 )
goto err;
@@ -2523,6 +2581,7 @@ static int __init construct_domU(struct domain *d,
struct kernel_info kinfo = {};
int rc;
u64 mem;
+ u32 len;
rc = dt_property_read_u64(node, "memory", &mem);
if ( !rc )
@@ -2534,6 +2593,8 @@ static int __init construct_domU(struct domain *d,
printk("*** LOADING DOMU cpus=%u memory=%luKB ***\n", d->max_vcpus, mem);
+ kinfo.vpl011 = dt_get_property(node, "vpl011", &len) != NULL;
+
d->vcpu = xzalloc_array(struct vcpu *, d->max_vcpus);
if ( !d->vcpu )
return -ENOMEM;;
diff --git a/xen/arch/arm/kernel.h b/xen/arch/arm/kernel.h
index 4320f72..33f3e72 100644
--- a/xen/arch/arm/kernel.h
+++ b/xen/arch/arm/kernel.h
@@ -33,6 +33,9 @@ struct kernel_info {
paddr_t dtb_paddr;
paddr_t initrd_paddr;
+ /* Enable pl011 emulation */
+ bool vpl011;
+
/* loader to use for this kernel */
void (*load)(struct kernel_info *info);
/* loader specific state */
