linux/drivers/hv/hv.c
Dan Carpenter 415f0a02ad hv: fix return type of hv_post_message()
This function returns negative error codes, but because the type is u16
they get truncated into positive numbers.  It doesn't look like the
callers care, but we should fix it anyway as a cleanup.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09 15:05:47 -07:00

428 lines
11 KiB
C

/*
* Copyright (c) 2009, Microsoft Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <asm/hyperv.h>
#include "hyperv_vmbus.h"
/* The one and only */
struct hv_context hv_context = {
.synic_initialized = false,
.hypercall_page = NULL,
.signal_event_param = NULL,
.signal_event_buffer = NULL,
};
/*
* query_hypervisor_presence
* - Query the cpuid for presence of windows hypervisor
*/
static int query_hypervisor_presence(void)
{
unsigned int eax;
unsigned int ebx;
unsigned int ecx;
unsigned int edx;
unsigned int op;
eax = 0;
ebx = 0;
ecx = 0;
edx = 0;
op = HVCPUID_VERSION_FEATURES;
cpuid(op, &eax, &ebx, &ecx, &edx);
return ecx & HV_PRESENT_BIT;
}
/*
* query_hypervisor_info - Get version info of the windows hypervisor
*/
static int query_hypervisor_info(void)
{
unsigned int eax;
unsigned int ebx;
unsigned int ecx;
unsigned int edx;
unsigned int max_leaf;
unsigned int op;
/*
* Its assumed that this is called after confirming that Viridian
* is present. Query id and revision.
*/
eax = 0;
ebx = 0;
ecx = 0;
edx = 0;
op = HVCPUID_VENDOR_MAXFUNCTION;
cpuid(op, &eax, &ebx, &ecx, &edx);
max_leaf = eax;
if (max_leaf >= HVCPUID_VERSION) {
eax = 0;
ebx = 0;
ecx = 0;
edx = 0;
op = HVCPUID_VERSION;
cpuid(op, &eax, &ebx, &ecx, &edx);
pr_info("Hyper-V Host OS Build:%d-%d.%d-%d-%d.%d\n",
eax,
ebx >> 16,
ebx & 0xFFFF,
ecx,
edx >> 24,
edx & 0xFFFFFF);
}
return max_leaf;
}
/*
* do_hypercall- Invoke the specified hypercall
*/
static u64 do_hypercall(u64 control, void *input, void *output)
{
#ifdef CONFIG_X86_64
u64 hv_status = 0;
u64 input_address = (input) ? virt_to_phys(input) : 0;
u64 output_address = (output) ? virt_to_phys(output) : 0;
void *hypercall_page = hv_context.hypercall_page;
__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
__asm__ __volatile__("call *%3" : "=a" (hv_status) :
"c" (control), "d" (input_address),
"m" (hypercall_page));
return hv_status;
#else
u32 control_hi = control >> 32;
u32 control_lo = control & 0xFFFFFFFF;
u32 hv_status_hi = 1;
u32 hv_status_lo = 1;
u64 input_address = (input) ? virt_to_phys(input) : 0;
u32 input_address_hi = input_address >> 32;
u32 input_address_lo = input_address & 0xFFFFFFFF;
u64 output_address = (output) ? virt_to_phys(output) : 0;
u32 output_address_hi = output_address >> 32;
u32 output_address_lo = output_address & 0xFFFFFFFF;
void *hypercall_page = hv_context.hypercall_page;
__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
"=a"(hv_status_lo) : "d" (control_hi),
"a" (control_lo), "b" (input_address_hi),
"c" (input_address_lo), "D"(output_address_hi),
"S"(output_address_lo), "m" (hypercall_page));
return hv_status_lo | ((u64)hv_status_hi << 32);
#endif /* !x86_64 */
}
/*
* hv_init - Main initialization routine.
*
* This routine must be called before any other routines in here are called
*/
int hv_init(void)
{
int max_leaf;
union hv_x64_msr_hypercall_contents hypercall_msr;
void *virtaddr = NULL;
memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
memset(hv_context.synic_message_page, 0,
sizeof(void *) * NR_CPUS);
if (!query_hypervisor_presence())
goto cleanup;
max_leaf = query_hypervisor_info();
/* Write our OS info */
wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
hv_context.guestid = HV_LINUX_GUEST_ID;
/* See if the hypercall page is already set */
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
if (!virtaddr)
goto cleanup;
hypercall_msr.enable = 1;
hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
/* Confirm that hypercall page did get setup. */
hypercall_msr.as_uint64 = 0;
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
if (!hypercall_msr.enable)
goto cleanup;
hv_context.hypercall_page = virtaddr;
/* Setup the global signal event param for the signal event hypercall */
hv_context.signal_event_buffer =
kmalloc(sizeof(struct hv_input_signal_event_buffer),
GFP_KERNEL);
if (!hv_context.signal_event_buffer)
goto cleanup;
hv_context.signal_event_param =
(struct hv_input_signal_event *)
(ALIGN((unsigned long)
hv_context.signal_event_buffer,
HV_HYPERCALL_PARAM_ALIGN));
hv_context.signal_event_param->connectionid.asu32 = 0;
hv_context.signal_event_param->connectionid.u.id =
VMBUS_EVENT_CONNECTION_ID;
hv_context.signal_event_param->flag_number = 0;
hv_context.signal_event_param->rsvdz = 0;
return 0;
cleanup:
if (virtaddr) {
if (hypercall_msr.enable) {
hypercall_msr.as_uint64 = 0;
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
}
vfree(virtaddr);
}
return -ENOTSUPP;
}
/*
* hv_cleanup - Cleanup routine.
*
* This routine is called normally during driver unloading or exiting.
*/
void hv_cleanup(void)
{
union hv_x64_msr_hypercall_contents hypercall_msr;
/* Reset our OS id */
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
kfree(hv_context.signal_event_buffer);
hv_context.signal_event_buffer = NULL;
hv_context.signal_event_param = NULL;
if (hv_context.hypercall_page) {
hypercall_msr.as_uint64 = 0;
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
vfree(hv_context.hypercall_page);
hv_context.hypercall_page = NULL;
}
}
/*
* hv_post_message - Post a message using the hypervisor message IPC.
*
* This involves a hypercall.
*/
int hv_post_message(union hv_connection_id connection_id,
enum hv_message_type message_type,
void *payload, size_t payload_size)
{
struct aligned_input {
u64 alignment8;
struct hv_input_post_message msg;
};
struct hv_input_post_message *aligned_msg;
u16 status;
unsigned long addr;
if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
return -EMSGSIZE;
addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
if (!addr)
return -ENOMEM;
aligned_msg = (struct hv_input_post_message *)
(ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
aligned_msg->connectionid = connection_id;
aligned_msg->message_type = message_type;
aligned_msg->payload_size = payload_size;
memcpy((void *)aligned_msg->payload, payload, payload_size);
status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
& 0xFFFF;
kfree((void *)addr);
return status;
}
/*
* hv_signal_event -
* Signal an event on the specified connection using the hypervisor event IPC.
*
* This involves a hypercall.
*/
u16 hv_signal_event(void)
{
u16 status;
status = do_hypercall(HVCALL_SIGNAL_EVENT,
hv_context.signal_event_param,
NULL) & 0xFFFF;
return status;
}
/*
* hv_synic_init - Initialize the Synthethic Interrupt Controller.
*
* If it is already initialized by another entity (ie x2v shim), we need to
* retrieve the initialized message and event pages. Otherwise, we create and
* initialize the message and event pages.
*/
void hv_synic_init(void *irqarg)
{
u64 version;
union hv_synic_simp simp;
union hv_synic_siefp siefp;
union hv_synic_sint shared_sint;
union hv_synic_scontrol sctrl;
u32 irq_vector = *((u32 *)(irqarg));
int cpu = smp_processor_id();
if (!hv_context.hypercall_page)
return;
/* Check the version */
rdmsrl(HV_X64_MSR_SVERSION, version);
hv_context.synic_message_page[cpu] =
(void *)get_zeroed_page(GFP_ATOMIC);
if (hv_context.synic_message_page[cpu] == NULL) {
pr_err("Unable to allocate SYNIC message page\n");
goto cleanup;
}
hv_context.synic_event_page[cpu] =
(void *)get_zeroed_page(GFP_ATOMIC);
if (hv_context.synic_event_page[cpu] == NULL) {
pr_err("Unable to allocate SYNIC event page\n");
goto cleanup;
}
/* Setup the Synic's message page */
rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
simp.simp_enabled = 1;
simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
>> PAGE_SHIFT;
wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
/* Setup the Synic's event page */
rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
siefp.siefp_enabled = 1;
siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
>> PAGE_SHIFT;
wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
/* Setup the shared SINT. */
rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
shared_sint.as_uint64 = 0;
shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
shared_sint.masked = false;
shared_sint.auto_eoi = false;
wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
/* Enable the global synic bit */
rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
sctrl.enable = 1;
wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
hv_context.synic_initialized = true;
return;
cleanup:
if (hv_context.synic_event_page[cpu])
free_page((unsigned long)hv_context.synic_event_page[cpu]);
if (hv_context.synic_message_page[cpu])
free_page((unsigned long)hv_context.synic_message_page[cpu]);
return;
}
/*
* hv_synic_cleanup - Cleanup routine for hv_synic_init().
*/
void hv_synic_cleanup(void *arg)
{
union hv_synic_sint shared_sint;
union hv_synic_simp simp;
union hv_synic_siefp siefp;
int cpu = smp_processor_id();
if (!hv_context.synic_initialized)
return;
rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
shared_sint.masked = 1;
/* Need to correctly cleanup in the case of SMP!!! */
/* Disable the interrupt */
wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
simp.simp_enabled = 0;
simp.base_simp_gpa = 0;
wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
siefp.siefp_enabled = 0;
siefp.base_siefp_gpa = 0;
wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
free_page((unsigned long)hv_context.synic_message_page[cpu]);
free_page((unsigned long)hv_context.synic_event_page[cpu]);
}