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authorWei Huang <wei.huang2@amd.com>2021-08-20 15:29:55 -0500
committerJoerg Roedel <jroedel@suse.de>2021-09-09 13:15:02 +0200
commitc3811a50addd23b9bb5a36278609ee1638debcf6 (patch)
treee18a2e9b803c38193e6f8a12cc2716a4282d892f /drivers/iommu
parentd8768d7eb9c21ef928adb93402d9348bcc4a6915 (diff)
iommu/amd: Relocate GAMSup check to early_enable_iommus
Currently, iommu_init_ga() checks and disables IOMMU VAPIC support (i.e. AMD AVIC support in IOMMU) when GAMSup feature bit is not set. However it forgets to clear IRQ_POSTING_CAP from the previously set amd_iommu_irq_ops.capability. This triggers an invalid page fault bug during guest VM warm reboot if AVIC is enabled since the irq_remapping_cap(IRQ_POSTING_CAP) is incorrectly set, and crash the system with the following kernel trace. BUG: unable to handle page fault for address: 0000000000400dd8 RIP: 0010:amd_iommu_deactivate_guest_mode+0x19/0xbc Call Trace: svm_set_pi_irte_mode+0x8a/0xc0 [kvm_amd] ? kvm_make_all_cpus_request_except+0x50/0x70 [kvm] kvm_request_apicv_update+0x10c/0x150 [kvm] svm_toggle_avic_for_irq_window+0x52/0x90 [kvm_amd] svm_enable_irq_window+0x26/0xa0 [kvm_amd] vcpu_enter_guest+0xbbe/0x1560 [kvm] ? avic_vcpu_load+0xd5/0x120 [kvm_amd] ? kvm_arch_vcpu_load+0x76/0x240 [kvm] ? svm_get_segment_base+0xa/0x10 [kvm_amd] kvm_arch_vcpu_ioctl_run+0x103/0x590 [kvm] kvm_vcpu_ioctl+0x22a/0x5d0 [kvm] __x64_sys_ioctl+0x84/0xc0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes by moving the initializing of AMD IOMMU interrupt remapping mode (amd_iommu_guest_ir) earlier before setting up the amd_iommu_irq_ops.capability with appropriate IRQ_POSTING_CAP flag. [joro: Squashed the two patches and limited check_features_on_all_iommus() to CONFIG_IRQ_REMAP to fix a compile warning.] Signed-off-by: Wei Huang <wei.huang2@amd.com> Co-developed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Link: https://lore.kernel.org/r/20210820202957.187572-2-suravee.suthikulpanit@amd.com Link: https://lore.kernel.org/r/20210820202957.187572-3-suravee.suthikulpanit@amd.com Fixes: 8bda0cfbdc1a ("iommu/amd: Detect and initialize guest vAPIC log") Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/amd/init.c31
1 files changed, 24 insertions, 7 deletions
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index bdcf167b4afe..4e753d1860b3 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -297,6 +297,22 @@ int amd_iommu_get_num_iommus(void)
return amd_iommus_present;
}
+#ifdef CONFIG_IRQ_REMAP
+static bool check_feature_on_all_iommus(u64 mask)
+{
+ bool ret = false;
+ struct amd_iommu *iommu;
+
+ for_each_iommu(iommu) {
+ ret = iommu_feature(iommu, mask);
+ if (!ret)
+ return false;
+ }
+
+ return true;
+}
+#endif
+
/*
* For IVHD type 0x11/0x40, EFR is also available via IVHD.
* Default to IVHD EFR since it is available sooner
@@ -853,13 +869,6 @@ static int iommu_init_ga(struct amd_iommu *iommu)
int ret = 0;
#ifdef CONFIG_IRQ_REMAP
- /* Note: We have already checked GASup from IVRS table.
- * Now, we need to make sure that GAMSup is set.
- */
- if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
- !iommu_feature(iommu, FEATURE_GAM_VAPIC))
- amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
-
ret = iommu_init_ga_log(iommu);
#endif /* CONFIG_IRQ_REMAP */
@@ -2479,6 +2488,14 @@ static void early_enable_iommus(void)
}
#ifdef CONFIG_IRQ_REMAP
+ /*
+ * Note: We have already checked GASup from IVRS table.
+ * Now, we need to make sure that GAMSup is set.
+ */
+ if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
+ !check_feature_on_all_iommus(FEATURE_GAM_VAPIC))
+ amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
+
if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
amd_iommu_irq_ops.capability |= (1 << IRQ_POSTING_CAP);
#endif