/*

 * Portions are:

 *  Copyright (c) 2002 Pavel Machek <pavel@suse.cz>

 *  Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>

 */

#include <xen/acpi.h>

#include <xen/smp.h>

#include <asm/processor.h>

#include <asm/msr.h>

#include <asm/debugreg.h>

#include <asm/hvm/hvm.h>

#include <asm/hvm/support.h>

#include <asm/i387.h>

#include <asm/xstate.h>

#include <xen/hypercall.h>

static unsigned long saved_lstar, saved_cstar;

static unsigned long saved_sysenter_esp, saved_sysenter_eip;

static unsigned long saved_fs_base, saved_gs_base, saved_kernel_gs_base;

static uint16_t saved_segs[4];

static uint64_t saved_xcr0;

void save_rest_processor_state(void)

{

    vcpu_save_fpu(current);

    asm volatile (

        "movw %%ds,(%0); movw %%es,2(%0); movw %%fs,4(%0); movw %%gs,6(%0)"

        : : "r" (saved_segs) : "memory" );

    saved_fs_base = rdfsbase();

    saved_gs_base = rdgsbase();

    rdmsrl(MSR_SHADOW_GS_BASE, saved_kernel_gs_base);

    rdmsrl(MSR_CSTAR, saved_cstar);

    rdmsrl(MSR_LSTAR, saved_lstar);

    if ( boot_cpu_data.x86_vendor == X86_VENDOR_INTEL ||

         boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR )

    {

        rdmsrl(MSR_IA32_SYSENTER_ESP, saved_sysenter_esp);

        rdmsrl(MSR_IA32_SYSENTER_EIP, saved_sysenter_eip);

    }

    if ( cpu_has_xsave )

        saved_xcr0 = get_xcr0();

}

void restore_rest_processor_state(void)

{

    struct vcpu *curr = current;

    load_TR();

    /* Recover syscall MSRs */

    wrmsrl(MSR_LSTAR, saved_lstar);

    wrmsrl(MSR_CSTAR, saved_cstar);

    wrmsrl(MSR_STAR, XEN_MSR_STAR);

    wrmsrl(MSR_SYSCALL_MASK, XEN_SYSCALL_MASK);

    wrfsbase(saved_fs_base);

    wrgsbase(saved_gs_base);

    wrmsrl(MSR_SHADOW_GS_BASE, saved_kernel_gs_base);

    if ( boot_cpu_data.x86_vendor == X86_VENDOR_INTEL ||

         boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR )

    {

        /* Recover sysenter MSRs */

        wrmsrl(MSR_IA32_SYSENTER_ESP, saved_sysenter_esp);

        wrmsrl(MSR_IA32_SYSENTER_EIP, saved_sysenter_eip);

        wrmsr(MSR_IA32_SYSENTER_CS, __HYPERVISOR_CS, 0);

    }

    if ( !is_idle_vcpu(curr) )

    {

        asm volatile (

            "movw (%0),%%ds; movw 2(%0),%%es; movw 4(%0),%%fs"

            : : "r" (saved_segs) : "memory" );

        do_set_segment_base(SEGBASE_GS_USER_SEL, saved_segs[3]);

    }

    if ( cpu_has_xsave && !set_xcr0(saved_xcr0) )

        BUG();

    /* Maybe load the debug registers. */

    BUG_ON(!is_pv_vcpu(curr));

    if ( !is_idle_vcpu(curr) && curr->arch.debugreg[7] )

    {

        write_debugreg(0, curr->arch.debugreg[0]);

        write_debugreg(1, curr->arch.debugreg[1]);

        write_debugreg(2, curr->arch.debugreg[2]);

        write_debugreg(3, curr->arch.debugreg[3]);

        write_debugreg(6, curr->arch.debugreg[6]);

        write_debugreg(7, curr->arch.debugreg[7]);

    }

    /* Reload FPU state on next FPU use. */

    stts();

    if (cpu_has_pat)

        wrmsrl(MSR_IA32_CR_PAT, host_pat);

    mtrr_bp_restore();

}