Commit f28558d3 authored by Will Auld's avatar Will Auld Committed by Marcelo Tosatti
Browse files

target-i386: Enabling IA32_TSC_ADJUST for QEMU KVM guest VMs 



CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported

Basic design is to emulate the MSR by allowing reads and writes to the
hypervisor vcpu specific locations to store the value of the emulated MSRs.
In this way the IA32_TSC_ADJUST value will be included in all reads to
the TSC MSR whether through rdmsr or rdtsc.

As this is a new MSR that the guest may access and modify its value needs
to be migrated along with the other MRSs. The changes here are specifically
for recognizing when IA32_TSC_ADJUST is enabled in CPUID and code added
for migrating its value.

Signed-off-by: default avatarWill Auld <will.auld@intel.com>
Reviewed-by: default avatarAndreas Färber <afaerber@suse.de>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent e376a788

target-i386/cpu.h

+2 −0
Original line number Diff line number Diff line
@@ -295,6 +295,7 @@ 
#define MSR_IA32_APICBASE_BSP           (1<<8)

#define MSR_IA32_APICBASE_ENABLE        (1<<11)

#define MSR_IA32_APICBASE_BASE          (0xfffff<<12)

#define MSR_TSC_ADJUST                  0x0000003b

#define MSR_IA32_TSCDEADLINE            0x6e0



#define MSR_MTRRcap			0xfe
@@ -774,6 +775,7 @@ typedef struct CPUX86State { 
    uint64_t pv_eoi_en_msr;



    uint64_t tsc;

    uint64_t tsc_adjust;

    uint64_t tsc_deadline;



    uint64_t mcg_status;

target-i386/kvm.c

+14 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = { 


static bool has_msr_star;

static bool has_msr_hsave_pa;

static bool has_msr_tsc_adjust;

static bool has_msr_tsc_deadline;

static bool has_msr_async_pf_en;

static bool has_msr_pv_eoi_en;
@@ -676,6 +677,10 @@ static int kvm_get_supported_msrs(KVMState *s) 
                    has_msr_hsave_pa = true;

                    continue;

                }

                if (kvm_msr_list->indices[i] == MSR_TSC_ADJUST) {

                    has_msr_tsc_adjust = true;

                    continue;

                }

                if (kvm_msr_list->indices[i] == MSR_IA32_TSCDEADLINE) {

                    has_msr_tsc_deadline = true;

                    continue;
@@ -1013,6 +1018,9 @@ static int kvm_put_msrs(CPUX86State *env, int level) 
    if (has_msr_hsave_pa) {

        kvm_msr_entry_set(&msrs[n++], MSR_VM_HSAVE_PA, env->vm_hsave);

    }

    if (has_msr_tsc_adjust) {

        kvm_msr_entry_set(&msrs[n++], MSR_TSC_ADJUST, env->tsc_adjust);

    }

    if (has_msr_tsc_deadline) {

        kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSCDEADLINE, env->tsc_deadline);

    }
@@ -1273,6 +1281,9 @@ static int kvm_get_msrs(CPUX86State *env) 
    if (has_msr_hsave_pa) {

        msrs[n++].index = MSR_VM_HSAVE_PA;

    }

    if (has_msr_tsc_adjust) {

        msrs[n++].index = MSR_TSC_ADJUST;

    }

    if (has_msr_tsc_deadline) {

        msrs[n++].index = MSR_IA32_TSCDEADLINE;

    }
@@ -1350,6 +1361,9 @@ static int kvm_get_msrs(CPUX86State *env) 
        case MSR_IA32_TSC:

            env->tsc = msrs[i].data;

            break;

        case MSR_TSC_ADJUST:

            env->tsc_adjust = msrs[i].data;

            break;

        case MSR_IA32_TSCDEADLINE:

            env->tsc_deadline = msrs[i].data;

            break;

target-i386/machine.c

+21 −0
Original line number Diff line number Diff line
@@ -328,6 +328,24 @@ static const VMStateDescription vmstate_fpop_ip_dp = { 
    }

};



static bool tsc_adjust_needed(void *opaque)

{

    CPUX86State *env = opaque;



    return env->tsc_adjust != 0;

}



static const VMStateDescription vmstate_msr_tsc_adjust = {

    .name = "cpu/msr_tsc_adjust",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields      = (VMStateField[]) {

        VMSTATE_UINT64(tsc_adjust, CPUX86State),

        VMSTATE_END_OF_LIST()

    }

};



static bool tscdeadline_needed(void *opaque)

{

    CPUX86State *env = opaque;
@@ -477,6 +495,9 @@ static const VMStateDescription vmstate_cpu = { 
        } , {

            .vmsd = &vmstate_fpop_ip_dp,

            .needed = fpop_ip_dp_needed,

        }, {

            .vmsd = &vmstate_msr_tsc_adjust,

            .needed = tsc_adjust_needed,

        }, {

            .vmsd = &vmstate_msr_tscdeadline,

            .needed = tscdeadline_needed,