xen/efi: introduce a PV interface for EFI run time services for dom0

FreeBSD when running as a dom0 under Xen is not supposed to access the
run time services directly, and instead should proxy the calls through
Xen using an hypercall interface that exposes access to selected run
time services.

Implement the efirt interface on top of the Xen provided hypercalls.

Sponsored by:		Citrix Systems R&D
Reviewed by:		kib
Differential revision:	https://reviews.freebsd.org/D28621
This commit is contained in:
Roger Pau Monné 2021-02-12 13:11:34 +01:00
parent 27d3902679
commit 952667da98
2 changed files with 256 additions and 0 deletions

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@ -3534,6 +3534,7 @@ dev/xen/blkfront/blkfront.c optional xenhvm
dev/xen/blkback/blkback.c optional xenhvm
dev/xen/console/xen_console.c optional xenhvm
dev/xen/control/control.c optional xenhvm
dev/xen/efi/pvefi.c optional xenhvm efirt
dev/xen/grant_table/grant_table.c optional xenhvm
dev/xen/netback/netback.c optional xenhvm
dev/xen/netfront/netfront.c optional xenhvm

255
sys/dev/xen/efi/pvefi.c Normal file
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@ -0,0 +1,255 @@
/*-
* Copyright (c) 2021 Citrix Systems R&D
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/efi.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/clock.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <xen/xen-os.h>
#include <xen/error.h>
#include <xen/hypervisor.h>
#include <xen/interface/platform.h>
extern char bootmethod[16];
static int
rt_ok(void)
{
return (0);
}
static int
get_time(struct efi_tm *tm)
{
struct xen_platform_op op = {
.cmd = XENPF_efi_runtime_call,
.u.efi_runtime_call.function = XEN_EFI_get_time,
};
struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
int error;
error = HYPERVISOR_platform_op(&op);
if (error != 0)
return (xen_translate_error(error));
tm->tm_year = call->u.get_time.time.year;
tm->tm_mon = call->u.get_time.time.month;
tm->tm_mday = call->u.get_time.time.day;
tm->tm_hour = call->u.get_time.time.hour;
tm->tm_min = call->u.get_time.time.min;
tm->tm_sec = call->u.get_time.time.sec;
tm->tm_nsec = call->u.get_time.time.ns;
tm->tm_tz = call->u.get_time.time.tz;
tm->tm_dst = call->u.get_time.time.daylight;
return (efi_status_to_errno(call->status));
}
static int
get_time_capabilities(struct efi_tmcap *tmcap)
{
struct xen_platform_op op = {
.cmd = XENPF_efi_runtime_call,
.u.efi_runtime_call.function = XEN_EFI_get_time,
};
struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
int error;
error = HYPERVISOR_platform_op(&op);
if (error != 0)
return (xen_translate_error(error));
tmcap->tc_res = call->u.get_time.resolution;
tmcap->tc_prec = call->u.get_time.accuracy;
tmcap->tc_stz = call->misc & XEN_EFI_GET_TIME_SET_CLEARS_NS;
return (efi_status_to_errno(call->status));
}
static int
set_time(struct efi_tm *tm)
{
struct xen_platform_op op = {
.cmd = XENPF_efi_runtime_call,
.u.efi_runtime_call.function = XEN_EFI_get_time,
.u.efi_runtime_call.u.set_time.year = tm->tm_year,
.u.efi_runtime_call.u.set_time.month = tm->tm_mon,
.u.efi_runtime_call.u.set_time.day = tm->tm_mday,
.u.efi_runtime_call.u.set_time.hour = tm->tm_hour,
.u.efi_runtime_call.u.set_time.min = tm->tm_min,
.u.efi_runtime_call.u.set_time.sec = tm->tm_sec,
.u.efi_runtime_call.u.set_time.ns = tm->tm_nsec,
.u.efi_runtime_call.u.set_time.tz = tm->tm_tz,
.u.efi_runtime_call.u.set_time.daylight = tm->tm_dst,
};
int error;
error = HYPERVISOR_platform_op(&op);
return ((error != 0) ? xen_translate_error(error) :
efi_status_to_errno(op.u.efi_runtime_call.status));
}
static int
var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
size_t *datasize, void *data)
{
struct xen_platform_op op = {
.cmd = XENPF_efi_runtime_call,
.u.efi_runtime_call.function = XEN_EFI_get_variable,
.u.efi_runtime_call.u.get_variable.size = *datasize,
};
struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
int error;
CTASSERT(sizeof(*vendor) == sizeof(call->u.get_variable.vendor_guid));
memcpy(&call->u.get_variable.vendor_guid, vendor,
sizeof(*vendor));
set_xen_guest_handle(call->u.get_variable.name, name);
set_xen_guest_handle(call->u.get_variable.data, data);
error = HYPERVISOR_platform_op(&op);
if (error != 0)
return (xen_translate_error(error));
*attrib = call->misc;
*datasize = call->u.get_variable.size;
return (efi_status_to_errno(call->status));
}
static int
var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
{
struct xen_platform_op op = {
.cmd = XENPF_efi_runtime_call,
.u.efi_runtime_call.function = XEN_EFI_get_next_variable_name,
.u.efi_runtime_call.u.get_next_variable_name.size = *namesize,
};
struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
int error;
memcpy(&call->u.get_next_variable_name.vendor_guid, vendor,
sizeof(*vendor));
set_xen_guest_handle(call->u.get_next_variable_name.name, name);
error = HYPERVISOR_platform_op(&op);
if (error != 0)
return (xen_translate_error(error));
*namesize = call->u.get_next_variable_name.size;
memcpy(vendor, &call->u.get_next_variable_name.vendor_guid,
sizeof(*vendor));
return (efi_status_to_errno(call->status));
}
static int
var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
size_t datasize, void *data)
{
struct xen_platform_op op = {
.cmd = XENPF_efi_runtime_call,
.u.efi_runtime_call.function = XEN_EFI_set_variable,
.u.efi_runtime_call.misc = attrib,
.u.efi_runtime_call.u.set_variable.size = datasize,
};
struct xenpf_efi_runtime_call *call = &op.u.efi_runtime_call;
int error;
memcpy(&call->u.set_variable.vendor_guid, vendor,
sizeof(*vendor));
set_xen_guest_handle(call->u.set_variable.name, name);
set_xen_guest_handle(call->u.set_variable.data, data);
error = HYPERVISOR_platform_op(&op);
return ((error != 0) ? xen_translate_error(error) :
efi_status_to_errno(call->status));
}
const static struct efi_ops pvefi_ops = {
.rt_ok = rt_ok,
.get_time = get_time,
.get_time_capabilities = get_time_capabilities,
.set_time = set_time,
.var_get = var_get,
.var_nextname = var_nextname,
.var_set = var_set,
};
static int
modevents(module_t m, int event, void *arg __unused)
{
const static struct efi_ops *prev;
int rt_disabled;
switch (event) {
case MOD_LOAD:
rt_disabled = 0;
TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
if (!xen_initial_domain() || strcmp("UEFI", bootmethod) != 0 ||
rt_disabled == 1)
return (0);
prev = active_efi_ops;
active_efi_ops = &pvefi_ops;
return (0);
case MOD_UNLOAD:
if (prev != NULL)
active_efi_ops = prev;
return (0);
case MOD_SHUTDOWN:
return (0);
default:
return (EOPNOTSUPP);
}
}
static moduledata_t moddata = {
.name = "pvefirt",
.evhand = modevents,
.priv = NULL,
};
/* After fpuinitstate, before efidev */
DECLARE_MODULE(pvefirt, moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
MODULE_VERSION(pvefirt, 1);