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| author | Christoffer Dall <christoffer.dall@linaro.org> | 2015-07-21 11:18:45 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2015-07-21 11:18:45 +0100 |
| commit | 4b7a6bf402bd064605c287eecadc493ccf2d4897 (patch) | |
| tree | 2da235a74cae51293675444895aaa89a507bd1ac /target-arm/kvm_arm.h | |
| parent | a1bc040dabc12039944e22d9529f20d6132400dd (diff) | |
| download | qemu-4b7a6bf402bd064605c287eecadc493ccf2d4897.tar.gz | |
target-arm: kvm: Differentiate registers based on write-back levels
Some registers like the CNTVCT register should only be written to the
kernel as part of machine initialization or on vmload operations, but
never during runtime, as this can potentially make time go backwards or
create inconsistent time observations between VCPUs.
Introduce a list of registers that should not be written back at runtime
and check this list on syncing the register state to the KVM state.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Message-id: 1437046488-10773-1-git-send-email-christoffer.dall@linaro.org
[PMM: tweaked a few comments, added the new argument to the stub
write_list_to_kvmstate() in target-arm/kvm-stub.c]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target-arm/kvm_arm.h')
| -rw-r--r-- | target-arm/kvm_arm.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/target-arm/kvm_arm.h b/target-arm/kvm_arm.h index 5abd5916d1..7912d7433d 100644 --- a/target-arm/kvm_arm.h +++ b/target-arm/kvm_arm.h @@ -69,8 +69,18 @@ int kvm_arm_init_cpreg_list(ARMCPU *cpu); bool kvm_arm_reg_syncs_via_cpreg_list(uint64_t regidx); /** + * kvm_arm_cpreg_level + * regidx: KVM register index + * + * Return the level of this coprocessor/system register. Return value is + * either KVM_PUT_RUNTIME_STATE, KVM_PUT_RESET_STATE, or KVM_PUT_FULL_STATE. + */ +int kvm_arm_cpreg_level(uint64_t regidx); + +/** * write_list_to_kvmstate: * @cpu: ARMCPU + * @level: the state level to sync * * For each register listed in the ARMCPU cpreg_indexes list, write * its value from the cpreg_values list into the kernel (via ioctl). @@ -83,7 +93,7 @@ bool kvm_arm_reg_syncs_via_cpreg_list(uint64_t regidx); * Note that we do not stop early on failure -- we will attempt * writing all registers in the list. */ -bool write_list_to_kvmstate(ARMCPU *cpu); +bool write_list_to_kvmstate(ARMCPU *cpu, int level); /** * write_kvmstate_to_list: |