From 7a56b81c474619fa84c60d07eaa287c8fc33ac3c Mon Sep 17 00:00:00 2001 From: Ralf Ramsauer Date: Thu, 10 Oct 2019 12:21:02 +0200 Subject: [PATCH] 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 Signed-off-by: Borislav Petkov Reviewed-by: Jan Kiszka Cc: Baoquan He Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: jailhouse-dev@googlegroups.com Cc: Juergen Gross Cc: "Kirill A. Shutemov" Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20191010102102.421035-3-ralf.ramsauer@oth-regensburg.de --- arch/x86/include/uapi/asm/bootparam.h | 3 + arch/x86/kernel/jailhouse.c | 85 +++++++++++++++++++++++---- 2 files changed, 75 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index 43be437c9c71..db1e24e56e94 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -152,6 +152,9 @@ struct jailhouse_setup_data { __u8 standard_ioapic; __u8 cpu_ids[255]; } __attribute__((packed)) v1; + struct { + __u32 flags; + } __attribute__((packed)) v2; } __attribute__((packed)); /* The so-called "zeropage" */ diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c index cf4eb37ad97b..6eb8b50ea07e 100644 --- a/arch/x86/kernel/jailhouse.c +++ b/arch/x86/kernel/jailhouse.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -21,11 +22,24 @@ #include #include -static __initdata struct jailhouse_setup_data setup_data; +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 || @@ -79,11 +93,6 @@ static void __init jailhouse_get_smp_config(unsigned int early) .type = IOAPIC_DOMAIN_STRICT, .ops = &mp_ioapic_irqdomain_ops, }; - struct mpc_intsrc mp_irq = { - .type = MP_INTSRC, - .irqtype = mp_INT, - .irqflag = MP_IRQPOL_ACTIVE_HIGH | MP_IRQTRIG_EDGE, - }; unsigned int cpu; jailhouse_x2apic_init(); @@ -100,12 +109,12 @@ static void __init jailhouse_get_smp_config(unsigned int early) if (setup_data.v1.standard_ioapic) { mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg); - /* Register 1:1 mapping for legacy UART IRQs 3 and 4 */ - mp_irq.srcbusirq = mp_irq.dstirq = 3; - mp_save_irq(&mp_irq); - - mp_irq.srcbusirq = mp_irq.dstirq = 4; - mp_save_irq(&mp_irq); + 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); + } } } @@ -138,6 +147,53 @@ static int __init jailhouse_pci_arch_init(void) 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; @@ -189,7 +245,8 @@ static void __init jailhouse_init_platform(void) 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 == 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; @@ -205,6 +262,8 @@ static void __init jailhouse_init_platform(void) * are none in a non-root cell. */ disable_acpi(); + + jailhouse_serial_workaround(); return; unsupported: