From: Richard Henderson <richard.henderson@linaro.org>
To: Cornelia Huck <cohuck@redhat.com>,
Peter Maydell <peter.maydell@linaro.org>,
Thomas Huth <thuth@redhat.com>,
Laurent Vivier <lvivier@redhat.com>
Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org, kvm@vger.kernel.org,
Eric Auger <eauger@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Juan Quintela <quintela@redhat.com>,
Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v4 1/2] arm/kvm: add support for MTE
Date: Tue, 17 Jan 2023 09:37:42 -1000 [thread overview]
Message-ID: <b92e6786-acc6-50ef-8804-e4e3ef4eb2d6@linaro.org> (raw)
In-Reply-To: <20230111161317.52250-2-cohuck@redhat.com>
On 1/11/23 06:13, Cornelia Huck wrote:
> @@ -2136,7 +2136,7 @@ static void machvirt_init(MachineState *machine)
>
> if (vms->mte && (kvm_enabled() || hvf_enabled())) {
> error_report("mach-virt: %s does not support providing "
> - "MTE to the guest CPU",
> + "emulated MTE to the guest CPU",
> kvm_enabled() ? "KVM" : "HVF");
Not your bug, but noticing this should use current_accel_name().
> +static inline bool arm_machine_has_tag_memory(void)
> +{
> +#ifndef CONFIG_USER_ONLY
> + Object *obj = object_dynamic_cast(qdev_get_machine(), TYPE_VIRT_MACHINE);
> +
> + /* so far, only the virt machine has support for tag memory */
> + if (obj) {
> + VirtMachineState *vms = VIRT_MACHINE(obj);
> +
> + return vms->mte;
> + }
> +#endif
> + return false;
> +}
True for CONFIG_USER_ONLY, via page_get_target_data().
You should have seen check-tcg test failures...
> +void arm_cpu_mte_finalize(ARMCPU *cpu, Error **errp)
> +{
> + bool enable_mte;
> +
> + switch (cpu->prop_mte) {
> + case ON_OFF_AUTO_OFF:
> + enable_mte = false;
> + break;
> + case ON_OFF_AUTO_ON:
> + if (!kvm_enabled()) {
tcg_enabled(), here and everywhere else you test for !kvm.
> +#ifdef CONFIG_KVM
> + if (kvm_enabled() && !kvm_arm_mte_supported()) {
kvm_arm.h should get a stub inline returning false, so that the ifdef is removed.
See e.g. kvm_arm_sve_supported().
> + default: /* AUTO */
> + if (!kvm_enabled()) {
tcg_enabled.
> + /* accelerator-specific enablement */
> + if (kvm_enabled()) {
> +#ifdef CONFIG_KVM
> + if (kvm_vm_enable_cap(kvm_state, KVM_CAP_ARM_MTE, 0)) {
> + error_setg(errp, "Failed to enable KVM_CAP_ARM_MTE");
Ideally this ifdef could go away as well.
> + } else {
> + /* TODO: add proper migration support with MTE enabled */
> + if (!mte_migration_blocker) {
Move the global variable here, as a local static?
I guess this check is to avoid adding one blocker per cpu?
I would guess the cap doesn't need enabling more than once either?
> + error_setg(&mte_migration_blocker,
> + "Live migration disabled due to MTE enabled");
> + if (migrate_add_blocker(mte_migration_blocker, NULL)) {
You pass NULL to the migrate_add_blocker errp argument...
> + error_setg(errp, "Failed to add MTE migration blocker");
... then make up your own generic reason for why it failed.
In this case it seems only related to another command-line option: --only-migratable.
Anyway, I wonder about hiding all of this in target/arm/kvm.c:
bool kvm_arm_enable_mte(Error *errp)
{
static bool once = false;
Error *blocker;
if (once) {
return;
}
once = true;
if (kvm_vm_enable_cap(kvm_state, KVM_CAP_ARM_MTE, 0)) {
error_setg_errno(errp, "Failed to enable KVM_CAP_ARM_MTE");
return false;
}
blocker = g_new0(Error);
error_setg(blocker, "Live migration disabled....");
return !migrate_add_blocker(blocker, errp);
}
with
static inline bool kvm_arm_enable_mte(Error *errp)
{
g_assert_not_reached();
}
in the !CONFIG_KVM block in kvm_arm.h.
next prev parent reply other threads:[~2023-01-17 19:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-11 16:13 [PATCH v4 0/2] arm: enable MTE for QEMU + kvm Cornelia Huck
2023-01-11 16:13 ` [PATCH v4 1/2] arm/kvm: add support for MTE Cornelia Huck
2023-01-17 16:16 ` Peter Maydell
2023-01-17 16:50 ` Dr. David Alan Gilbert
2023-01-17 16:59 ` Cornelia Huck
2023-01-17 17:11 ` Dr. David Alan Gilbert
2023-01-17 17:01 ` Peter Maydell
2023-01-17 17:53 ` Dr. David Alan Gilbert
2023-01-17 16:52 ` Cornelia Huck
2023-01-17 19:37 ` Richard Henderson [this message]
2023-01-18 17:37 ` Cornelia Huck
2023-01-23 13:50 ` Eric Auger
2023-01-26 11:47 ` Cornelia Huck
2023-01-26 12:15 ` Cornelia Huck
2023-01-11 16:13 ` [PATCH v4 2/2] qtests/arm: add some mte tests Cornelia Huck
2023-01-17 7:21 ` Philippe Mathieu-Daudé
2023-01-23 14:29 ` Eric Auger
2023-01-26 10:57 ` Cornelia Huck
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