linux-kernel - [PATCH 06/10] iommu/amd: KVM: SVM: Use pi_desc_addr to derive ga_root

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230815213533.548732-7-seanjc@google.com>
Date:   Tue, 15 Aug 2023 14:35:29 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Joerg Roedel <joro@...tes.org>
Cc:     kvm@...r.kernel.org, iommu@...ts.linux.dev,
        linux-kernel@...r.kernel.org, Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH 06/10] iommu/amd: KVM: SVM: Use pi_desc_addr to derive ga_root_ptr

Use vcpu_data.pi_desc_addr instead of amd_iommu_pi_data.base to get the
GA root pointer.  KVM is the only source of amd_iommu_pi_data.base, and
KVM's one and only path for writing amd_iommu_pi_data.base computes the
exact same value for vcpu_data.pi_desc_addr and amd_iommu_pi_data.base,
and fills amd_iommu_pi_data.base if and only if vcpu_data.pi_desc_addr is
valid, i.e. amd_iommu_pi_data.base is fully redundant.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/avic.c   | 1 -
 drivers/iommu/amd/iommu.c | 2 +-
 include/linux/amd-iommu.h | 1 -
 3 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index e49b682c8469..bd81e3517838 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -919,7 +919,6 @@ int avic_pi_update_irte(struct kvm *kvm, unsigned int host_irq,
 			struct amd_iommu_pi_data pi;
 
 			/* Try to enable guest_mode in IRTE */
-			pi.base = avic_get_backing_page_address(svm);
 			pi.ga_tag = AVIC_GATAG(to_kvm_svm(kvm)->avic_vm_id,
 						     svm->vcpu.vcpu_id);
 			pi.is_guest_mode = true;
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index c3b58a8389b9..9814df73b9a7 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3622,7 +3622,7 @@ static int amd_ir_set_vcpu_affinity(struct irq_data *data, void *vcpu_info)
 
 	pi_data->prev_ga_tag = ir_data->cached_ga_tag;
 	if (pi_data->is_guest_mode) {
-		ir_data->ga_root_ptr = (pi_data->base >> 12);
+		ir_data->ga_root_ptr = (vcpu_pi_info->pi_desc_addr >> 12);
 		ir_data->ga_vector = vcpu_pi_info->vector;
 		ir_data->ga_tag = pi_data->ga_tag;
 		ret = amd_iommu_activate_guest_mode(ir_data);
diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index 953e6f12fa1c..30d19ad0e8a9 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -20,7 +20,6 @@ struct amd_iommu;
 struct amd_iommu_pi_data {
 	u32 ga_tag;
 	u32 prev_ga_tag;
-	u64 base;
 	bool is_guest_mode;
 	struct vcpu_data *vcpu_data;
 	void *ir_data;
-- 
2.41.0.694.ge786442a9b-goog