linux/arch/x86/kernel/jailhouse.c
Ralf Ramsauer 7a56b81c47 x86/jailhouse: Only enable platform UARTs if available
ACPI tables aren't available if Linux runs as guest of the hypervisor
Jailhouse. This makes the 8250 driver probe for all platform UARTs as it
assumes that all UARTs are present in case of !ACPI. Jailhouse will stop
execution of Linux guest due to port access violation.

So far, these access violations were solved by tuning the 8250.nr_uarts
cmdline parameter, but this has limitations: Only consecutive platform
UARTs can be mapped to Linux, and only in the sequence 0x3f8, 0x2f8,
0x3e8, 0x2e8.

Beginning from setup_data version 2, Jailhouse will place information of
available platform UARTs in setup_data. This allows for selective
activation of platform UARTs.

Query setup_data version and only activate available UARTS. This
patch comes with backward compatibility, and will still support older
setup_data versions. In case of older setup_data versions, Linux falls
back to the old behaviour.

Signed-off-by: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: jailhouse-dev@googlegroups.com
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191010102102.421035-3-ralf.ramsauer@oth-regensburg.de
2019-10-10 15:43:59 +02:00

294 lines
7.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Jailhouse paravirt_ops implementation
*
* Copyright (c) Siemens AG, 2015-2017
*
* Authors:
* Jan Kiszka <jan.kiszka@siemens.com>
*/
#include <linux/acpi_pmtmr.h>
#include <linux/kernel.h>
#include <linux/reboot.h>
#include <linux/serial_8250.h>
#include <asm/apic.h>
#include <asm/cpu.h>
#include <asm/hypervisor.h>
#include <asm/i8259.h>
#include <asm/irqdomain.h>
#include <asm/pci_x86.h>
#include <asm/reboot.h>
#include <asm/setup.h>
#include <asm/jailhouse_para.h>
static struct jailhouse_setup_data setup_data;
#define SETUP_DATA_V1_LEN (sizeof(setup_data.hdr) + sizeof(setup_data.v1))
#define SETUP_DATA_V2_LEN (SETUP_DATA_V1_LEN + sizeof(setup_data.v2))
static unsigned int precalibrated_tsc_khz;
static void jailhouse_setup_irq(unsigned int irq)
{
struct mpc_intsrc mp_irq = {
.type = MP_INTSRC,
.irqtype = mp_INT,
.irqflag = MP_IRQPOL_ACTIVE_HIGH | MP_IRQTRIG_EDGE,
.srcbusirq = irq,
.dstirq = irq,
};
mp_save_irq(&mp_irq);
}
static uint32_t jailhouse_cpuid_base(void)
{
if (boot_cpu_data.cpuid_level < 0 ||
!boot_cpu_has(X86_FEATURE_HYPERVISOR))
return 0;
return hypervisor_cpuid_base("Jailhouse\0\0\0", 0);
}
static uint32_t __init jailhouse_detect(void)
{
return jailhouse_cpuid_base();
}
static void jailhouse_get_wallclock(struct timespec64 *now)
{
memset(now, 0, sizeof(*now));
}
static void __init jailhouse_timer_init(void)
{
lapic_timer_period = setup_data.v1.apic_khz * (1000 / HZ);
}
static unsigned long jailhouse_get_tsc(void)
{
return precalibrated_tsc_khz;
}
static void __init jailhouse_x2apic_init(void)
{
#ifdef CONFIG_X86_X2APIC
if (!x2apic_enabled())
return;
/*
* We do not have access to IR inside Jailhouse non-root cells. So
* we have to run in physical mode.
*/
x2apic_phys = 1;
/*
* This will trigger the switch to apic_x2apic_phys. Empty OEM IDs
* ensure that only this APIC driver picks up the call.
*/
default_acpi_madt_oem_check("", "");
#endif
}
static void __init jailhouse_get_smp_config(unsigned int early)
{
struct ioapic_domain_cfg ioapic_cfg = {
.type = IOAPIC_DOMAIN_STRICT,
.ops = &mp_ioapic_irqdomain_ops,
};
unsigned int cpu;
jailhouse_x2apic_init();
register_lapic_address(0xfee00000);
for (cpu = 0; cpu < setup_data.v1.num_cpus; cpu++) {
generic_processor_info(setup_data.v1.cpu_ids[cpu],
boot_cpu_apic_version);
}
smp_found_config = 1;
if (setup_data.v1.standard_ioapic) {
mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);
if (IS_ENABLED(CONFIG_SERIAL_8250) &&
setup_data.hdr.version < 2) {
/* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
jailhouse_setup_irq(3);
jailhouse_setup_irq(4);
}
}
}
static void jailhouse_no_restart(void)
{
pr_notice("Jailhouse: Restart not supported, halting\n");
machine_halt();
}
static int __init jailhouse_pci_arch_init(void)
{
pci_direct_init(1);
/*
* There are no bridges on the virtual PCI root bus under Jailhouse,
* thus no other way to discover all devices than a full scan.
* Respect any overrides via the command line, though.
*/
if (pcibios_last_bus < 0)
pcibios_last_bus = 0xff;
#ifdef CONFIG_PCI_MMCONFIG
if (setup_data.v1.pci_mmconfig_base) {
pci_mmconfig_add(0, 0, pcibios_last_bus,
setup_data.v1.pci_mmconfig_base);
pci_mmcfg_arch_init();
}
#endif
return 0;
}
#ifdef CONFIG_SERIAL_8250
static inline bool jailhouse_uart_enabled(unsigned int uart_nr)
{
return setup_data.v2.flags & BIT(uart_nr);
}
static void jailhouse_serial_fixup(int port, struct uart_port *up,
u32 *capabilities)
{
static const u16 pcuart_base[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8};
unsigned int n;
for (n = 0; n < ARRAY_SIZE(pcuart_base); n++) {
if (pcuart_base[n] != up->iobase)
continue;
if (jailhouse_uart_enabled(n)) {
pr_info("Enabling UART%u (port 0x%lx)\n", n,
up->iobase);
jailhouse_setup_irq(up->irq);
} else {
/* Deactivate UART if access isn't allowed */
up->iobase = 0;
}
break;
}
}
static void __init jailhouse_serial_workaround(void)
{
/*
* There are flags inside setup_data that indicate availability of
* platform UARTs since setup data version 2.
*
* In case of version 1, we don't know which UARTs belong Linux. In
* this case, unconditionally register 1:1 mapping for legacy UART IRQs
* 3 and 4.
*/
if (setup_data.hdr.version > 1)
serial8250_set_isa_configurator(jailhouse_serial_fixup);
}
#else /* !CONFIG_SERIAL_8250 */
static inline void jailhouse_serial_workaround(void)
{
}
#endif /* CONFIG_SERIAL_8250 */
static void __init jailhouse_init_platform(void)
{
u64 pa_data = boot_params.hdr.setup_data;
unsigned long setup_data_len;
struct setup_data header;
void *mapping;
x86_init.irqs.pre_vector_init = x86_init_noop;
x86_init.timers.timer_init = jailhouse_timer_init;
x86_init.mpparse.get_smp_config = jailhouse_get_smp_config;
x86_init.pci.arch_init = jailhouse_pci_arch_init;
x86_platform.calibrate_cpu = jailhouse_get_tsc;
x86_platform.calibrate_tsc = jailhouse_get_tsc;
x86_platform.get_wallclock = jailhouse_get_wallclock;
x86_platform.legacy.rtc = 0;
x86_platform.legacy.warm_reset = 0;
x86_platform.legacy.i8042 = X86_LEGACY_I8042_PLATFORM_ABSENT;
legacy_pic = &null_legacy_pic;
machine_ops.emergency_restart = jailhouse_no_restart;
while (pa_data) {
mapping = early_memremap(pa_data, sizeof(header));
memcpy(&header, mapping, sizeof(header));
early_memunmap(mapping, sizeof(header));
if (header.type == SETUP_JAILHOUSE)
break;
pa_data = header.next;
}
if (!pa_data)
panic("Jailhouse: No valid setup data found");
/* setup data must at least contain the header */
if (header.len < sizeof(setup_data.hdr))
goto unsupported;
pa_data += offsetof(struct setup_data, data);
setup_data_len = min_t(unsigned long, sizeof(setup_data),
(unsigned long)header.len);
mapping = early_memremap(pa_data, setup_data_len);
memcpy(&setup_data, mapping, setup_data_len);
early_memunmap(mapping, setup_data_len);
if (setup_data.hdr.version == 0 ||
setup_data.hdr.compatible_version !=
JAILHOUSE_SETUP_REQUIRED_VERSION ||
(setup_data.hdr.version == 1 && header.len < SETUP_DATA_V1_LEN) ||
(setup_data.hdr.version >= 2 && header.len < SETUP_DATA_V2_LEN))
goto unsupported;
pmtmr_ioport = setup_data.v1.pm_timer_address;
pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
precalibrated_tsc_khz = setup_data.v1.tsc_khz;
setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
pci_probe = 0;
/*
* Avoid that the kernel complains about missing ACPI tables - there
* are none in a non-root cell.
*/
disable_acpi();
jailhouse_serial_workaround();
return;
unsupported:
panic("Jailhouse: Unsupported setup data structure");
}
bool jailhouse_paravirt(void)
{
return jailhouse_cpuid_base() != 0;
}
static bool __init jailhouse_x2apic_available(void)
{
/*
* The x2APIC is only available if the root cell enabled it. Jailhouse
* does not support switching between xAPIC and x2APIC.
*/
return x2apic_enabled();
}
const struct hypervisor_x86 x86_hyper_jailhouse __refconst = {
.name = "Jailhouse",
.detect = jailhouse_detect,
.init.init_platform = jailhouse_init_platform,
.init.x2apic_available = jailhouse_x2apic_available,
.ignore_nopv = true,
};