superrob1500
/
mirror-linux
mirror of https://github.com/torvalds/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

arch/x86: mshyperv: Trap on access for some synthetic MSRs 

hv_set_non_nested_msr() has special handling for SINT MSRs
when a paravisor is present. In addition to updating the MSR on the
host, the mirror MSR in the paravisor is updated, including with the
proxy bit. But with Confidential VMBus, the proxy bit must not be
used, so add a special case to skip it.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
master
Roman Kisel 2025-10-08 16:34:07 -07:00 committed by Wei Liu
parent e6eeb3c782
commit a156ad8c50
3 changed files with 31 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
arch/x86/kernel/cpu/mshyperv.c
View File

@ -28,6 +28,7 @@
#include <asm/apic.h>
#include <asm/timer.h>
#include <asm/reboot.h>
#include <asm/msr.h>
#include <asm/nmi.h>
#include <clocksource/hyperv_timer.h>
#include <asm/msr.h>
@ -39,6 +40,12 @@ bool hv_nested;
struct ms_hyperv_info ms_hyperv;
#if IS_ENABLED(CONFIG_HYPERV)
/*
* When running with the paravisor, controls proxying the synthetic interrupts
* from the host
*/
static bool hv_para_sint_proxy;
static inline unsigned int hv_get_nested_msr(unsigned int reg)
{
if (hv_is_sint_msr(reg))
@ -75,17 +82,31 @@ EXPORT_SYMBOL_GPL(hv_get_non_nested_msr);
void hv_set_non_nested_msr(unsigned int reg, u64 value)
{
if (hv_is_synic_msr(reg) && ms_hyperv.paravisor_present) {
/* The hypervisor will get the intercept. */
hv_ivm_msr_write(reg, value);
/* Write proxy bit via wrmsl instruction */
if (hv_is_sint_msr(reg))
wrmsrq(reg, value | 1 << 20);
/* Using wrmsrq so the following goes to the paravisor. */
if (hv_is_sint_msr(reg)) {
union hv_synic_sint sint = { .as_uint64 = value };
sint.proxy = hv_para_sint_proxy;
native_wrmsrq(reg, sint.as_uint64);
}
} else {
wrmsrq(reg, value);
native_wrmsrq(reg, value);
}
}
EXPORT_SYMBOL_GPL(hv_set_non_nested_msr);
/*
* Enable or disable proxying synthetic interrupts
* to the paravisor.
*/
void hv_para_set_sint_proxy(bool enable)
{
hv_para_sint_proxy = enable;
}
/*
* Get the SynIC register value from the paravisor.
*/

5
drivers/hv/hv_common.c
View File

@ -721,6 +721,11 @@ void __weak hv_enable_coco_interrupt(unsigned int cpu, unsigned int vector, bool
}
EXPORT_SYMBOL_GPL(hv_enable_coco_interrupt);
void __weak hv_para_set_sint_proxy(bool enable)
{
}
EXPORT_SYMBOL_GPL(hv_para_set_sint_proxy);
u64 __weak hv_para_get_synic_register(unsigned int reg)
{
return ~0ULL;

1
include/asm-generic/mshyperv.h
View File

@ -310,6 +310,7 @@ bool hv_isolation_type_snp(void);
u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
void hv_enable_coco_interrupt(unsigned int cpu, unsigned int vector, bool set);
void hv_para_set_sint_proxy(bool enable);
u64 hv_para_get_synic_register(unsigned int reg);
void hv_para_set_synic_register(unsigned int reg, u64 val);
void hyperv_cleanup(void);