On Sat, 25 Feb 2023 20:48:01 +0000,
Shivam Kumar <shivam.kumar1@xxxxxxxxxxx> wrote:
>
> Call update_dirty_quota whenever a page is marked dirty with
> appropriate arch-specific page size. Process the KVM request
> KVM_REQ_DIRTY_QUOTA_EXIT (raised by update_dirty_quota) to exit to
> userspace with exit reason KVM_EXIT_DIRTY_QUOTA_EXHAUSTED.
>
> Suggested-by: Shaju Abraham <shaju.abraham@xxxxxxxxxxx>
> Suggested-by: Manish Mishra <manish.mishra@xxxxxxxxxxx>
> Co-developed-by: Anurag Madnawat <anurag.madnawat@xxxxxxxxxxx>
> Signed-off-by: Anurag Madnawat <anurag.madnawat@xxxxxxxxxxx>
> Signed-off-by: Shivam Kumar <shivam.kumar1@xxxxxxxxxxx>
> ---
> arch/arm64/kvm/Kconfig | 1 +
> arch/arm64/kvm/arm.c | 7 +++++++
> arch/arm64/kvm/mmu.c | 3 +++
> 3 files changed, 11 insertions(+)
>
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index ca6eadeb7d1a..8e7dea2c3a9f 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -44,6 +44,7 @@ menuconfig KVM
> select SCHED_INFO
> select GUEST_PERF_EVENTS if PERF_EVENTS
> select INTERVAL_TREE
> + select HAVE_KVM_DIRTY_QUOTA
So this is selected unconditionally...
> help
> Support hosting virtualized guest machines.
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 3bd732eaf087..5162b2fc46a1 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -757,6 +757,13 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu)
>
> if (kvm_dirty_ring_check_request(vcpu))
> return 0;
> +
> +#ifdef CONFIG_HAVE_KVM_DIRTY_QUOTA
... and yet you litter the arch code with #ifdefs...
> + if (kvm_check_request(KVM_REQ_DIRTY_QUOTA_EXIT, vcpu)) {
> + vcpu->run->exit_reason = KVM_EXIT_DIRTY_QUOTA_EXHAUSTED;
> + return 0;
What rechecks the quota on entry?
> + }
> +#endif
> }
>
> return 1;
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 7113587222ff..baf416046f46 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1390,6 +1390,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
> /* Mark the page dirty only if the fault is handled successfully */
> if (writable && !ret) {
> kvm_set_pfn_dirty(pfn);
> +#ifdef CONFIG_HAVE_KVM_DIRTY_QUOTA
> + update_dirty_quota(kvm, fault_granule);
fault_granule isn't necessarily the amount that gets dirtied.
M.
--
Without deviation from the norm, progress is not possible.
