linux/arch/x86/hyperv/nested.c
Joseph Salisbury 753ed9c95c drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00

137 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Hyper-V nested virtualization code.
*
* Copyright (C) 2018, Microsoft, Inc.
*
* Author : Lan Tianyu <Tianyu.Lan@microsoft.com>
*/
#define pr_fmt(fmt) "Hyper-V: " fmt
#include <linux/types.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
#include <asm/tlbflush.h>
#include <asm/trace/hyperv.h>
int hyperv_flush_guest_mapping(u64 as)
{
struct hv_guest_mapping_flush **flush_pcpu;
struct hv_guest_mapping_flush *flush;
u64 status;
unsigned long flags;
int ret = -ENOTSUPP;
if (!hv_hypercall_pg)
goto fault;
local_irq_save(flags);
flush_pcpu = (struct hv_guest_mapping_flush **)
this_cpu_ptr(hyperv_pcpu_input_arg);
flush = *flush_pcpu;
if (unlikely(!flush)) {
local_irq_restore(flags);
goto fault;
}
flush->address_space = as;
flush->flags = 0;
status = hv_do_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE,
flush, NULL);
local_irq_restore(flags);
if (hv_result_success(status))
ret = 0;
fault:
trace_hyperv_nested_flush_guest_mapping(as, ret);
return ret;
}
EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping);
int hyperv_fill_flush_guest_mapping_list(
struct hv_guest_mapping_flush_list *flush,
u64 start_gfn, u64 pages)
{
u64 cur = start_gfn;
u64 additional_pages;
int gpa_n = 0;
do {
/*
* If flush requests exceed max flush count, go back to
* flush tlbs without range.
*/
if (gpa_n >= HV_MAX_FLUSH_REP_COUNT)
return -ENOSPC;
additional_pages = min_t(u64, pages, HV_MAX_FLUSH_PAGES) - 1;
flush->gpa_list[gpa_n].page.additional_pages = additional_pages;
flush->gpa_list[gpa_n].page.largepage = false;
flush->gpa_list[gpa_n].page.basepfn = cur;
pages -= additional_pages + 1;
cur += additional_pages + 1;
gpa_n++;
} while (pages > 0);
return gpa_n;
}
EXPORT_SYMBOL_GPL(hyperv_fill_flush_guest_mapping_list);
int hyperv_flush_guest_mapping_range(u64 as,
hyperv_fill_flush_list_func fill_flush_list_func, void *data)
{
struct hv_guest_mapping_flush_list **flush_pcpu;
struct hv_guest_mapping_flush_list *flush;
u64 status;
unsigned long flags;
int ret = -ENOTSUPP;
int gpa_n = 0;
if (!hv_hypercall_pg || !fill_flush_list_func)
goto fault;
local_irq_save(flags);
flush_pcpu = (struct hv_guest_mapping_flush_list **)
this_cpu_ptr(hyperv_pcpu_input_arg);
flush = *flush_pcpu;
if (unlikely(!flush)) {
local_irq_restore(flags);
goto fault;
}
flush->address_space = as;
flush->flags = 0;
gpa_n = fill_flush_list_func(flush, data);
if (gpa_n < 0) {
local_irq_restore(flags);
goto fault;
}
status = hv_do_rep_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST,
gpa_n, 0, flush, NULL);
local_irq_restore(flags);
if (hv_result_success(status))
ret = 0;
else
ret = hv_result(status);
fault:
trace_hyperv_nested_flush_guest_mapping_range(as, ret);
return ret;
}
EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping_range);