Re: git: 927358dd98cb - main - amd64 loader: Use efiserialio for Hyper-V booted systems
Date: Fri, 31 Mar 2023 06:22:17 UTC
> On 31. Mar 2023, at 02:40, Warner Losh <imp@bsdimp.com> wrote:
>
> Let's back it out. I didn't get a chance to review it and the duplicated name strikes me as massively unwise.
> Of course, the efi serial driver never should have had the name comconsole in the first place, imho. It was OK
> on arm where we couldn't conflict.
>
> So let's back it out and talk about how we should do this, including the need to possibly just rename the efi
> version of the console driver to something else. IMHO, it never should have been comconsole in the first
> place because it's configured differently than comconsole....
>
> Warner
ok, lets start from beginning. The loader device naming is total mess and should not go this way - it is not understandable for users and not understandable for developers.
the config below is perfect example of the situation:
First the config does set:
>> console="comconsole vidconsole efi”
So, we do try to set serial console, bios video console and efi console. So we have “shared” config for BIOS and UEFI loader, which should be totally reasonable from user point of view, but is technically wrong, because BIOS loader has no idea what is efi console and EFI loader has no idea what is vidconsole. So this mixture ends up with message:
>> console vidconsole is invalid!"
And the user will get the similar error when booting BIOS setup.
Then we just set console=“efi”.
Then there is setting for uart…
With todays UEFI setups, the logic is that you set up your hardware, that is, you configure serial port attributes from firmware setup, and the UEFI firmware will populate its internal structures with those values.
Now, first issue is, while developing uefi loader, it was easy path to reuse bits from BIOS loader. smbios, acpi, and sadly, comconsole. Sadly, because comconsole is built assuming x86 IO port features which are not available on other platforms.
So yes, bios version of comconsole should not have been used to build UEFI loader at all.
Now the fun part, even as UEFI does provide SIO API to access serial ports, to read from port, write to port and set attributes, it turns out there are UEFI implementation(s?), where changing some attributes will cause system to hung. Which is the reason, why we need to set up hardware properly from firmware, and our generic config should not try to enforce some other value(s). Default should pick up values from the system. Sure, if the machine operator has some reason to change those values and has tested the change, we should have method to change the config, but again, defaults should come from system setup.
While I see the reasoning to try to create all those different names, maybe the first thing should be to look on this as innocent end user, who has no idea about those fine technical details and historical reasons and is just trying to get system to behave….
just my 2 cents,
toomas
>
> On Thu, Mar 30, 2023 at 5:31 PM Gleb Smirnoff <glebius@freebsd.org <mailto:glebius@freebsd.org>> wrote:
>> Wei, Kyle,
>>
>> this commit hangs loader on real hardware, at least on some
>> of it. The loader prints list of consoles and hangs hard:
>>
>> [Thu Mar 30 20:46:12 2023]^M|^HLoading /boot/loader.conf^M
>> ^M/^Hconsole vidconsole is invalid!^M
>> ^MAvailable consoles:^M
>> ^M efi^M
>> ^M comconsole^M
>> ^M comconsole^M
>> ^M nullconsole^M
>> ^M spinconsole^M
>>
>> Machine is unrecoverable unless you got alternate boot media
>> and access to BMC console.
>>
>> First, please DO NOT MFC this as scheduled. Second, let's try
>> to fix it or back it out if we hear from any other CURRENT
>> user.
>>
>> Our configuration isn't special. This is what we got in
>> loader.conf, related to consoles:
>>
>> console="comconsole vidconsole efi"
>> comconsole_speed=115200
>> comconsole_port=0x3e8
>> console="efi"
>> hw.uart.console="io:1016,br:115200"
>>
>> On Sat, Mar 18, 2023 at 07:20:33AM +0000, Wei Hu wrote:
>> W> The branch main has been updated by whu:
>> W>
>> W> URL: https://cgit.FreeBSD.org/src/commit/?id=927358dd98cb902160093e0dc0bac002d6b43858 <https://cgit.freebsd.org/src/commit/?id=927358dd98cb902160093e0dc0bac002d6b43858>
>> W>
>> W> commit 927358dd98cb902160093e0dc0bac002d6b43858
>> W> Author: Wei Hu <whu@FreeBSD.org>
>> W> AuthorDate: 2023-03-14 15:13:46 +0000
>> W> Commit: Wei Hu <whu@FreeBSD.org>
>> W> CommitDate: 2023-03-18 07:07:35 +0000
>> W>
>> W> amd64 loader: Use efiserialio for Hyper-V booted systems
>> W>
>> W> UEFI provides ConIn/ConOut handles for consoles that it supports,
>> W> which include the text-video and serial ports. When the serial port
>> W> is available, use the UEFI driver instead of direct io-port accesses
>> W> to avoid conflicts between the firmware and direct hardware access, as
>> W> happens on Hyper-V (Azure) setups.
>> W>
>> W> This change enables efiserialio to be built for efi-amd64 and has
>> W> higher order priority vs comconsole, and only uses efiserialio
>> W> if the hypervisor is Hyper-V. When efiserialio successfully
>> W> probes, it will set efi_comconsole_avail=true which will prevent
>> W> comconsole from probing in this setup.
>> W>
>> W> Tested on Hyper-V, ESXi and Azure VMs.
>> W>
>> W> PR: 264267
>> W> Reviewed by: kevans, whu
>> W> Tested by: whu
>> W> Obtained from: Rubicon Communications, LLC (Netgate)
>> W> MFC after: 2 weeks
>> W> Sponsored by: Rubicon Communications, LLC (Netgate)
>> W> ---
>> W> stand/efi/loader/arch/amd64/Makefile.inc | 1 +
>> W> stand/efi/loader/bootinfo.c | 11 ++++++--
>> W> stand/efi/loader/conf.c | 6 +++++
>> W> stand/efi/loader/efiserialio.c | 43 ++++++++++++++++++++++++++++----
>> W> stand/i386/libi386/comconsole.c | 14 +++++++++++
>> W> 5 files changed, 68 insertions(+), 7 deletions(-)
>> W>
>> W> diff --git a/stand/efi/loader/arch/amd64/Makefile.inc b/stand/efi/loader/arch/amd64/Makefile.inc
>> W> index 0d9e2648cb59..bd89044bd6c7 100644
>> W> --- a/stand/efi/loader/arch/amd64/Makefile.inc
>> W> +++ b/stand/efi/loader/arch/amd64/Makefile.inc
>> W> @@ -5,6 +5,7 @@ SRCS+= amd64_tramp.S \
>> W> elf64_freebsd.c \
>> W> trap.c \
>> W> multiboot2.c \
>> W> + efiserialio.c \
>> W> exc.S
>> W>
>> W> .PATH: ${BOOTSRC}/i386/libi386
>> W> diff --git a/stand/efi/loader/bootinfo.c b/stand/efi/loader/bootinfo.c
>> W> index 939f2cf4c3fe..d79f59343af1 100644
>> W> --- a/stand/efi/loader/bootinfo.c
>> W> +++ b/stand/efi/loader/bootinfo.c
>> W> @@ -119,10 +119,17 @@ bi_getboothowto(char *kargs)
>> W> if (tmp != NULL)
>> W> speed = strtol(tmp, NULL, 0);
>> W> tmp = getenv("efi_com_port");
>> W> - if (tmp == NULL)
>> W> - tmp = getenv("comconsole_port");
>> W> if (tmp != NULL)
>> W> port = strtol(tmp, NULL, 0);
>> W> + if (port <= 0) {
>> W> + tmp = getenv("comconsole_port");
>> W> + if (tmp != NULL)
>> W> + port = strtol(tmp, NULL, 0);
>> W> + else {
>> W> + if (port == 0)
>> W> + port = 0x3f8;
>> W> + }
>> W> + }
>> W> if (speed != -1 && port != -1) {
>> W> snprintf(buf, sizeof(buf), "io:%d,br:%d", port,
>> W> speed);
>> W> diff --git a/stand/efi/loader/conf.c b/stand/efi/loader/conf.c
>> W> index 863c9188c72c..051e1a3381d1 100644
>> W> --- a/stand/efi/loader/conf.c
>> W> +++ b/stand/efi/loader/conf.c
>> W> @@ -81,6 +81,9 @@ struct netif_driver *netif_drivers[] = {
>> W>
>> W> extern struct console efi_console;
>> W> extern struct console comconsole;
>> W> +#if defined(__amd64__)
>> W> +extern struct console eficomconsole;
>> W> +#endif
>> W> #if defined(__amd64__) || defined(__i386__)
>> W> extern struct console nullconsole;
>> W> extern struct console spinconsole;
>> W> @@ -88,6 +91,9 @@ extern struct console spinconsole;
>> W>
>> W> struct console *consoles[] = {
>> W> &efi_console,
>> W> +#if defined(__amd64__)
>> W> + &eficomconsole,
>> W> +#endif
>> W> &comconsole,
>> W> #if defined(__amd64__) || defined(__i386__)
>> W> &nullconsole,
>> W> diff --git a/stand/efi/loader/efiserialio.c b/stand/efi/loader/efiserialio.c
>> W> index 375e679d2590..5fbc700f6ac2 100644
>> W> --- a/stand/efi/loader/efiserialio.c
>> W> +++ b/stand/efi/loader/efiserialio.c
>> W> @@ -69,6 +69,11 @@ static int comc_speed_set(struct env_var *, int, const void *);
>> W>
>> W> static struct serial *comc_port;
>> W> extern struct console efi_console;
>> W> +bool efi_comconsole_avail = false;
>> W> +
>> W> +#if defined(__amd64__)
>> W> +#define comconsole eficomconsole
>> W> +#endif
>> W>
>> W> struct console comconsole = {
>> W> .c_name = "comconsole",
>> W> @@ -254,11 +259,22 @@ comc_probe(struct console *sc)
>> W> char *env, *buf, *ep;
>> W> size_t sz;
>> W>
>> W> +#if defined(__amd64__)
>> W> + /*
>> W> + * For x86-64, don't use this driver if not running in Hyper-V.
>> W> + */
>> W> + env = getenv("smbios.bios.version");
>> W> + if (env == NULL || strncmp(env, "Hyper-V", 7) != 0) {
>> W> + return;
>> W> + }
>> W> +#endif
>> W> +
>> W> if (comc_port == NULL) {
>> W> comc_port = calloc(1, sizeof (struct serial));
>> W> if (comc_port == NULL)
>> W> return;
>> W> }
>> W> +
>> W> /* Use defaults from firmware */
>> W> comc_port->databits = 8;
>> W> comc_port->parity = DefaultParity;
>> W> @@ -308,6 +324,10 @@ comc_probe(struct console *sc)
>> W> comc_port_set, env_nounset);
>> W>
>> W> env = getenv("efi_com_speed");
>> W> + if (env == NULL)
>> W> + /* fallback to comconsole setting */
>> W> + env = getenv("comconsole_speed");
>> W> +
>> W> if (comc_parse_intval(env, &val) == CMD_OK)
>> W> comc_port->baudrate = val;
>> W>
>> W> @@ -318,8 +338,13 @@ comc_probe(struct console *sc)
>> W> comc_speed_set, env_nounset);
>> W>
>> W> comconsole.c_flags = 0;
>> W> - if (comc_setup())
>> W> + if (comc_setup()) {
>> W> sc->c_flags = C_PRESENTIN | C_PRESENTOUT;
>> W> + efi_comconsole_avail = true;
>> W> + } else {
>> W> + /* disable being seen as "comconsole" */
>> W> + comconsole.c_name = "efiserialio";
>> W> + }
>> W> }
>> W>
>> W> static int
>> W> @@ -489,6 +514,7 @@ comc_setup(void)
>> W> {
>> W> EFI_STATUS status;
>> W> UINT32 control;
>> W> + char *ev;
>> W>
>> W> /* port is not usable */
>> W> if (comc_port->sio == NULL)
>> W> @@ -498,10 +524,17 @@ comc_setup(void)
>> W> if (EFI_ERROR(status))
>> W> return (false);
>> W>
>> W> - status = comc_port->sio->SetAttributes(comc_port->sio,
>> W> - comc_port->baudrate, comc_port->receivefifodepth,
>> W> - comc_port->timeout, comc_port->parity,
>> W> - comc_port->databits, comc_port->stopbits);
>> W> + ev = getenv("smbios.bios.version");
>> W> + if (ev != NULL && strncmp(ev, "Hyper-V", 7) == 0) {
>> W> + status = comc_port->sio->SetAttributes(comc_port->sio,
>> W> + 0, 0, 0, DefaultParity, 0, DefaultStopBits);
>> W> + } else {
>> W> + status = comc_port->sio->SetAttributes(comc_port->sio,
>> W> + comc_port->baudrate, comc_port->receivefifodepth,
>> W> + comc_port->timeout, comc_port->parity,
>> W> + comc_port->databits, comc_port->stopbits);
>> W> + }
>> W> +
>> W> if (EFI_ERROR(status))
>> W> return (false);
>> W>
>> W> diff --git a/stand/i386/libi386/comconsole.c b/stand/i386/libi386/comconsole.c
>> W> index ed1f1aa08ed7..3fbb6a292c19 100644
>> W> --- a/stand/i386/libi386/comconsole.c
>> W> +++ b/stand/i386/libi386/comconsole.c
>> W> @@ -85,6 +85,20 @@ comc_probe(struct console *cp)
>> W> int speed, port;
>> W> uint32_t locator;
>> W>
>> W> +#if defined(__amd64__)
>> W> + extern bool efi_comconsole_avail;
>> W> +
>> W> + if (efi_comconsole_avail) {
>> W> + /*
>> W> + * If EFI provides serial I/O, then don't use this legacy
>> W> + * com driver to avoid conflicts with the firmware's driver.
>> W> + * Change c_name so that it cannot be found in the lookup.
>> W> + */
>> W> + comconsole.c_name = "xcomconsole";
>> W> + return;
>> W> + }
>> W> +#endif
>> W> +
>> W> if (comc_curspeed == 0) {
>> W> comc_curspeed = COMSPEED;
>> W> /*
>>
>> --
>> Gleb Smirnoff