Hi Andre,
On 2/25/21 12:59 AM, Andre Przywara wrote:
> Using the RTC device at its legacy I/O address as set by IBM in 1981
> was a kludge we used for simplicity on ARM platforms as well.
> However this imposes problems due to their missing alignment and overlap
> with the PCI I/O address space.
>
> Now that we can switch a device easily between using ioports and
> MMIO, let's move the RTC out of the first 4K of memory on ARM platforms.
>
> That should be transparent for well behaved guests, since the change is
> naturally reflected in the device tree.
Everything looks correct, compile tested for arm64 and x86-64. Also grep'ed for
0x70 (device ioport address) and DEVICE_BUS_IOPORT, no occurrence in the file
other than in the defines:
Reviewed-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
Thanks,
Alex
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> arm/include/arm-common/kvm-arch.h | 3 +++
> hw/rtc.c | 24 ++++++++++++++++--------
> 2 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h
> index 633ea8fa..02100c48 100644
> --- a/arm/include/arm-common/kvm-arch.h
> +++ b/arm/include/arm-common/kvm-arch.h
> @@ -31,6 +31,9 @@
> #define ARM_UART_MMIO_BASE ARM_MMIO_AREA
> #define ARM_UART_MMIO_SIZE 0x10000
>
> +#define ARM_RTC_MMIO_BASE (ARM_UART_MMIO_BASE + ARM_UART_MMIO_SIZE)
> +#define ARM_RTC_MMIO_SIZE 0x10000
> +
> #define KVM_FLASH_MMIO_BASE (ARM_MMIO_AREA + 0x1000000)
> #define KVM_FLASH_MAX_SIZE 0x1000000
>
> diff --git a/hw/rtc.c b/hw/rtc.c
> index ee4c9102..aec31c52 100644
> --- a/hw/rtc.c
> +++ b/hw/rtc.c
> @@ -5,6 +5,15 @@
>
> #include <time.h>
>
> +#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
> +#define RTC_BUS_TYPE DEVICE_BUS_MMIO
> +#define RTC_BASE_ADDRESS ARM_RTC_MMIO_BASE
> +#else
> +/* PORT 0070-007F - CMOS RAM/RTC (REAL TIME CLOCK) */
> +#define RTC_BUS_TYPE DEVICE_BUS_IOPORT
> +#define RTC_BASE_ADDRESS 0x70
> +#endif
> +
> /*
> * MC146818 RTC registers
> */
> @@ -49,7 +58,7 @@ static void cmos_ram_io(struct kvm_cpu *vcpu, u64 addr, u8 *data,
> time_t ti;
>
> if (is_write) {
> - if (addr == 0x70) { /* index register */
> + if (addr == RTC_BASE_ADDRESS) { /* index register */
> u8 value = ioport__read8(data);
>
> vcpu->kvm->nmi_disabled = value & (1UL << 7);
> @@ -70,7 +79,7 @@ static void cmos_ram_io(struct kvm_cpu *vcpu, u64 addr, u8 *data,
> return;
> }
>
> - if (addr == 0x70)
> + if (addr == RTC_BASE_ADDRESS) /* index register is write-only */
> return;
>
> time(&ti);
> @@ -127,7 +136,7 @@ static void generate_rtc_fdt_node(void *fdt,
> u8 irq,
> enum irq_type))
> {
> - u64 reg_prop[2] = { cpu_to_fdt64(0x70), cpu_to_fdt64(2) };
> + u64 reg_prop[2] = { cpu_to_fdt64(RTC_BASE_ADDRESS), cpu_to_fdt64(2) };
>
> _FDT(fdt_begin_node(fdt, "rtc"));
> _FDT(fdt_property_string(fdt, "compatible", "motorola,mc146818"));
> @@ -139,7 +148,7 @@ static void generate_rtc_fdt_node(void *fdt,
> #endif
>
> struct device_header rtc_dev_hdr = {
> - .bus_type = DEVICE_BUS_IOPORT,
> + .bus_type = RTC_BUS_TYPE,
> .data = generate_rtc_fdt_node,
> };
>
> @@ -151,8 +160,8 @@ int rtc__init(struct kvm *kvm)
> if (r < 0)
> return r;
>
> - /* PORT 0070-007F - CMOS RAM/RTC (REAL TIME CLOCK) */
> - r = kvm__register_pio(kvm, 0x0070, 2, cmos_ram_io, NULL);
> + r = kvm__register_iotrap(kvm, RTC_BASE_ADDRESS, 2, cmos_ram_io, NULL,
> + RTC_BUS_TYPE);
> if (r < 0)
> goto out_device;
>
> @@ -170,8 +179,7 @@ dev_init(rtc__init);
>
> int rtc__exit(struct kvm *kvm)
> {
> - /* PORT 0070-007F - CMOS RAM/RTC (REAL TIME CLOCK) */
> - kvm__deregister_pio(kvm, 0x0070);
> + kvm__deregister_iotrap(kvm, RTC_BASE_ADDRESS, RTC_BUS_TYPE);
>
> return 0;
> }
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