From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 327A731A71; Thu, 7 Dec 2023 09:15:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I3enIjcB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFF49C433C7; Thu, 7 Dec 2023 09:15:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701940526; bh=/Ctyeihvym0TLJckEfSU+fK0IoOk5vWkpWC1s1zEMPM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=I3enIjcBzdi6ERkvUMs8ND5g/RZGWozPoSNu5732cRCy43npx7N7AXF7xHecPxUfr JLwONzeAnrGWYNeNo8et4zlC1VfSLm1zI+lcNSeQfXcG43eA+DDPi98h8grwMZ9IPT 3LqvHIEfyqgrul+aqRCIT32OxkXczh3fP0eQRuMgP9dOySk3nh7j9D079xJIO/9E5e r//l5DxlaUS92HGG69hxhjKqrIyy46OPYszmKMFw0pmP9vfgXwPGIRslihA8ZSBxyG QIhm1BdjGsvR+3cSHaMtn1MK9bO326agDzFHXPCb+4GdoBqKltUuNdEECEW9RGkLG3 7taPRy/0u0j3A== X-Mailer: emacs 29.1 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V (IBM) To: Vaibhav Jain , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Cc: Vaibhav Jain , Nicholas Piggin , Michael Ellerman , Jordan Niethe , Vaidyanathan Srinivasan , mikey@neuling.org, paulus@ozlabs.org, sbhat@linux.ibm.com, gautam@linux.ibm.com, kconsul@linux.vnet.ibm.com, amachhiw@linux.vnet.ibm.com, David.Laight@ACULAB.COM Subject: Re: [PATCH 01/12] KVM: PPC: Book3S HV nestedv2: Invalidate RPT before deleting a guest In-Reply-To: <20231201132618.555031-2-vaibhav@linux.ibm.com> References: <20231201132618.555031-1-vaibhav@linux.ibm.com> <20231201132618.555031-2-vaibhav@linux.ibm.com> Date: Thu, 07 Dec 2023 14:45:18 +0530 Message-ID: <878r66xtjt.fsf@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Vaibhav Jain writes: > From: Jordan Niethe > > An L0 must invalidate the L2's RPT during H_GUEST_DELETE if this has not > already been done. This is a slow operation that means H_GUEST_DELETE > must return H_BUSY multiple times before completing. Invalidating the > tables before deleting the guest so there is less work for the L0 to do. > > Signed-off-by: Jordan Niethe > --- > arch/powerpc/include/asm/kvm_book3s.h | 1 + > arch/powerpc/kvm/book3s_hv.c | 6 ++++-- > arch/powerpc/kvm/book3s_hv_nested.c | 2 +- > 3 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h > index 4f527d09c92b..a37736ed3728 100644 > --- a/arch/powerpc/include/asm/kvm_book3s.h > +++ b/arch/powerpc/include/asm/kvm_book3s.h > @@ -302,6 +302,7 @@ void kvmhv_nested_exit(void); > void kvmhv_vm_nested_init(struct kvm *kvm); > long kvmhv_set_partition_table(struct kvm_vcpu *vcpu); > long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu); > +void kvmhv_flush_lpid(u64 lpid); > void kvmhv_set_ptbl_entry(u64 lpid, u64 dw0, u64 dw1); > void kvmhv_release_all_nested(struct kvm *kvm); > long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu); > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 1ed6ec140701..5543e8490cd9 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -5691,10 +5691,12 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm) > kvmhv_set_ptbl_entry(kvm->arch.lpid, 0, 0); > } > > - if (kvmhv_is_nestedv2()) > + if (kvmhv_is_nestedv2()) { > + kvmhv_flush_lpid(kvm->arch.lpid); > plpar_guest_delete(0, kvm->arch.lpid); > I am not sure I follow the optimization here. I would expect the hypervisor to kill all the translation caches as part of guest_delete. What is the benefit of doing a lpid flush outside the guest delete? > - else > + } else { > kvmppc_free_lpid(kvm->arch.lpid); > + } > > kvmppc_free_pimap(kvm); > } > diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c > index 3b658b8696bc..5c375ec1a3c6 100644 > --- a/arch/powerpc/kvm/book3s_hv_nested.c > +++ b/arch/powerpc/kvm/book3s_hv_nested.c > @@ -503,7 +503,7 @@ void kvmhv_nested_exit(void) > } > } > > -static void kvmhv_flush_lpid(u64 lpid) > +void kvmhv_flush_lpid(u64 lpid) > { > long rc; > > -- > 2.42.0