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That's all we know. X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --vikpe6obnxeko6wi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 17, 2020 at 01:13:06PM +0200, Vitaly Kuznetsov wrote: > QEMU's kvmclock device is only created when KVM PV feature bits for > kvmclock (KVM_FEATURE_CLOCKSOURCE/KVM_FEATURE_CLOCKSOURCE2) are > exposed to the guest. With 'kvm=3Doff' cpu flag the device is not > created and we don't call KVM_GET_CLOCK/KVM_SET_CLOCK upon migration. > It was reported that without these call at least Hyper-V TSC page > clocksouce (which can be enabled independently) gets broken after > migration. >=20 > Switch to creating kvmclock QEMU device unconditionally, it seems > to always make sense to call KVM_GET_CLOCK/KVM_SET_CLOCK on migration. > Use KVM_CAP_ADJUST_CLOCK check instead of CPUID feature bits. >=20 > Reported-by: Antoine Damhet > Suggested-by: Paolo Bonzini > Signed-off-by: Vitaly Kuznetsov > --- > hw/i386/kvm/clock.c | 6 +----- > target/i386/kvm.c | 5 +++++ > target/i386/kvm_i386.h | 1 + > 3 files changed, 7 insertions(+), 5 deletions(-) >=20 > diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c > index 64283358f91d..526c9ea5172b 100644 > --- a/hw/i386/kvm/clock.c > +++ b/hw/i386/kvm/clock.c > @@ -330,11 +330,7 @@ static const TypeInfo kvmclock_info =3D { > /* Note: Must be called after VCPU initialization. */ > void kvmclock_create(void) > { > - X86CPU *cpu =3D X86_CPU(first_cpu); > - > - if (kvm_enabled() && > - cpu->env.features[FEAT_KVM] & ((1ULL << KVM_FEATURE_CLOCKSOURCE)= | > - (1ULL << KVM_FEATURE_CLOCKSOURCE2= ))) { > + if (kvm_enabled() && kvm_has_adjust_clock()) { Shouldn't the old check used when machine type <=3D 5.1 in order to avoid migration incompatibility ? > sysbus_create_simple(TYPE_KVM_CLOCK, -1, NULL); > } > } > diff --git a/target/i386/kvm.c b/target/i386/kvm.c > index 4a8b3a41c1bc..20b31b65307b 100644 > --- a/target/i386/kvm.c > +++ b/target/i386/kvm.c > @@ -143,6 +143,11 @@ bool kvm_has_adjust_clock_stable(void) > return (ret =3D=3D KVM_CLOCK_TSC_STABLE); > } > =20 > +bool kvm_has_adjust_clock(void) > +{ > + return kvm_check_extension(kvm_state, KVM_CAP_ADJUST_CLOCK); > +} > + > bool kvm_has_exception_payload(void) > { > return has_exception_payload; > diff --git a/target/i386/kvm_i386.h b/target/i386/kvm_i386.h > index 064b8798a26c..0fce4e51d2d6 100644 > --- a/target/i386/kvm_i386.h > +++ b/target/i386/kvm_i386.h > @@ -34,6 +34,7 @@ > =20 > bool kvm_allows_irq0_override(void); > bool kvm_has_smm(void); > +bool kvm_has_adjust_clock(void); > bool kvm_has_adjust_clock_stable(void); > bool kvm_has_exception_payload(void); > void kvm_synchronize_all_tsc(void); > --=20 > 2.25.4 >=20 >=20 --=20 Antoine 'xdbob' Damhet --vikpe6obnxeko6wi Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEArm1WbQx2GmOsfF83AmjLzzljz4FAl9jVdUACgkQ3AmjLzzl jz41ZggAgr4IGvlzgt8XS4LjT1qYjt+vr7IFjoceBn6d/Cou21MgV/fBGylABPfy KJBdJMO4tQ5FCQSlV30sAyFzsoMrKz8B6o4N8i2KVCPPNslH2eQBxaCSutoZWZUO xGtapD0xAMHwKqd6gjdyTO5YrEq/PdPH79mDiOn38ZDE422WnWiCEts1yMUX51Hk 4bCC89fV3w7oDj/lzrJs+kfQpybP/qH67OMv0FqJE5guhkiE27zxbMz+O0n47D0n E8UfXTEzXS/9ev1lP8vcuv+IJhm7tT44lEP2TMfl+UdBdMMCPpLKqoeummQ4HlB0 siWUMcmlB8Lmb+BYnPPF6gbM0rk4wQ== =Vqhs -----END PGP SIGNATURE----- --vikpe6obnxeko6wi--