msr.c

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#include "hal/cpu/msr.h"
 
void vxWRSR(uint32_t msr, uint64_t value) {
    // serial_printf("value : 0x%lx\n", value);
 
    uint32_t lo = (uint32_t) value;
    uint32_t hi = (uint32_t) (value >> 32);
    // serial_printf("wrmsr 0x%lx: hi=0x%lx lo=0x%lx\n", msr, hi, lo);
 
    asm volatile("wrmsr" : : "c"(msr), "a"(lo), "d"(hi) : "memory");
}
 
uint64_t vxRDMSR(uint32_t msr) {
    uint32_t lo, hi;
    __asm__ volatile("rdmsr" : "=a"(lo), "=d"(hi) : "c"(msr) : "memory");
    return ((uint64_t) hi << 32) | lo;
}
 
void msrSetFSBase(uint64_t base) {
    vxWRSR(MSR_FS_BASE, base);
}
 
void msrSetGSBase(uint64_t base) {
    vxWRSR(MSR_GS_BASE, base);
}
 
uintptr_t msrReadFSBase() {
    return vxRDMSR(MSR_FS_BASE);
}
 
uintptr_t msrReadGSBase() {
    return vxRDMSR(MSR_GS_BASE);
}
 
uintptr_t msrReadKernelGSBase() {
    return vxRDMSR(MSR_KERNEL_GS_BASE);
}
 
 
void msrSetKernelGSBase(uint64_t base) {
    vxWRSR(MSR_KERNEL_GS_BASE, base);
}