linux-kernel - [RFC PATCH 05/13] KVM: SVM: Update max number of vCPUs supported for x2AVIC mode

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: <20220221021922.733373-6-suravee.suthikulpanit@amd.com>
Date:   Sun, 20 Feb 2022 20:19:14 -0600
From:   Suravee Suthikulpanit <suravee.suthikulpanit@....com>
To:     <linux-kernel@...r.kernel.org>, <kvm@...r.kernel.org>
CC:     <pbonzini@...hat.com>, <seanjc@...gle.com>, <joro@...tes.org>,
        <jon.grimm@....com>, <wei.huang2@....com>, <terry.bowman@....com>,
        "Suravee Suthikulpanit" <suravee.suthikulpanit@....com>
Subject: [RFC PATCH 05/13] KVM: SVM: Update max number of vCPUs supported for x2AVIC mode

xAVIC and x2AVIC modes can support diffferent number of vcpus.
Update existing logics to support each mode accordingly.

Also, modify the maximum physical APIC ID for AVIC to 255 to reflect
the actual value supported by the architecture.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
---
 arch/x86/include/asm/svm.h | 12 +++++++++---
 arch/x86/kvm/svm/avic.c    |  8 +++++---
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 7a7a2297165b..681a348a9365 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -250,10 +250,16 @@ enum avic_ipi_failure_cause {
 
 
 /*
- * 0xff is broadcast, so the max index allowed for physical APIC ID
- * table is 0xfe.  APIC IDs above 0xff are reserved.
+ * For AVIC, the max index allowed for physical APIC ID
+ * table is 0xff (255).
  */
-#define AVIC_MAX_PHYSICAL_ID_COUNT	0xff
+#define AVIC_MAX_PHYSICAL_ID		0XFFULL
+
+/*
+ * For x2AVIC, the max index allowed for physical APIC ID
+ * table is 0x1ff (511).
+ */
+#define X2AVIC_MAX_PHYSICAL_ID		0x1FFUL
 
 #define AVIC_HPA_MASK	~((0xFFFULL << 52) | 0xFFF)
 #define VMCB_AVIC_APIC_BAR_MASK		0xFFFFFFFFFF000ULL
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 0040824e4376..1999076966fd 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -195,7 +195,7 @@ void avic_init_vmcb(struct vcpu_svm *svm)
 	vmcb->control.avic_backing_page = bpa & AVIC_HPA_MASK;
 	vmcb->control.avic_logical_id = lpa & AVIC_HPA_MASK;
 	vmcb->control.avic_physical_id = ppa & AVIC_HPA_MASK;
-	vmcb->control.avic_physical_id |= AVIC_MAX_PHYSICAL_ID_COUNT;
+	vmcb->control.avic_physical_id |= AVIC_MAX_PHYSICAL_ID;
 	vmcb->control.avic_vapic_bar = APIC_DEFAULT_PHYS_BASE & VMCB_AVIC_APIC_BAR_MASK;
 
 	if (kvm_apicv_activated(svm->vcpu.kvm))
@@ -210,7 +210,8 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu,
 	u64 *avic_physical_id_table;
 	struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm);
 
-	if (index >= AVIC_MAX_PHYSICAL_ID_COUNT)
+	if ((avic_mode == AVIC_MODE_X1 && index > AVIC_MAX_PHYSICAL_ID) ||
+	    (avic_mode == AVIC_MODE_X2 && index > X2AVIC_MAX_PHYSICAL_ID))
 		return NULL;
 
 	avic_physical_id_table = page_address(kvm_svm->avic_physical_id_table_page);
@@ -257,7 +258,8 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu)
 	int id = vcpu->vcpu_id;
 	struct vcpu_svm *svm = to_svm(vcpu);
 
-	if (id >= AVIC_MAX_PHYSICAL_ID_COUNT)
+	if ((avic_mode == AVIC_MODE_X1 && id > AVIC_MAX_PHYSICAL_ID) ||
+	    (avic_mode == AVIC_MODE_X2 && id > X2AVIC_MAX_PHYSICAL_ID))
 		return -EINVAL;
 
 	if (!vcpu->arch.apic->regs)
-- 
2.25.1