ANDROID: KVM: arm64: iommu: Add arg to finalize to pass state

Add an argument to finalize HVC/function that should be used from EL1
driver.
The argument holds standard error code. Incase of any error, pKVM
will erase pvmfw.

Bug: 268607700
Change-Id: I9f6a6bfc89d3381ab88938586d3b73dd5d94102a
Signed-off-by: Mostafa Saleh <smostafa@google.com>

arch/arm64/include/asm/kvm_host.h

@@ -401,8 +401,12 @@ int pkvm_iommu_register(struct device *dev, u64 drv,
 int pkvm_iommu_suspend(struct device *dev);
 int pkvm_iommu_resume(struct device *dev);
 
-/* Reject future calls to pkvm_iommu_driver_init() and pkvm_iommu_register(). */
-int pkvm_iommu_finalize(void);
+/*
+ * Reject future calls to pkvm_iommu_driver_init() and pkvm_iommu_register()
+ * and report errors if found. Incase of errors pKVM can take proper actions
+ * as erasing pvmfw.
+ */
+int pkvm_iommu_finalize(int err);
 
 struct vcpu_reset_state {
 	unsigned long	pc;

arch/arm64/kvm/hyp/include/nvhe/iommu.h

@@ -91,7 +91,7 @@ int __pkvm_iommu_register(unsigned long dev_id, unsigned long drv_id,
 			  void *kern_mem_va, size_t mem_size);
 int __pkvm_iommu_pm_notify(unsigned long dev_id,
 			   enum pkvm_iommu_pm_event event);
-int __pkvm_iommu_finalize(void);
+int __pkvm_iommu_finalize(int err);
 int pkvm_iommu_host_stage2_adjust_range(phys_addr_t addr, phys_addr_t *start,
 					phys_addr_t *end);
 bool pkvm_iommu_host_dabt_handler(struct kvm_cpu_context *host_ctxt, u32 esr,

arch/arm64/kvm/hyp/nvhe/hyp-main.c

@@ -1171,7 +1171,9 @@ static void handle___pkvm_iommu_pm_notify(struct kvm_cpu_context *host_ctxt)
 
 static void handle___pkvm_iommu_finalize(struct kvm_cpu_context *host_ctxt)
 {
-	cpu_reg(host_ctxt, 1) = __pkvm_iommu_finalize();
+	DECLARE_REG(int, err, host_ctxt, 1);
+
+	cpu_reg(host_ctxt, 1) = __pkvm_iommu_finalize(err);
 }
 
 static void handle___pkvm_alloc_module_va(struct kvm_cpu_context *host_ctxt)

arch/arm64/kvm/hyp/nvhe/iommu.c

@@ -14,6 +14,7 @@
 #include <hyp/adjust_pc.h>
 #include <nvhe/iommu.h>
 #include <nvhe/mm.h>
+#include <nvhe/pkvm.h>
 
 #define DRV_ID(drv_addr)			((unsigned long)drv_addr)
 
@@ -450,7 +451,7 @@ out_unlock:
 	return ret;
 }
 
-int __pkvm_iommu_finalize(void)
+int __pkvm_iommu_finalize(int err)
 {
 	int ret = 0;
 
@@ -460,6 +461,14 @@ int __pkvm_iommu_finalize(void)
 	else
 		ret = -EPERM;
 	hyp_spin_unlock(&iommu_registration_lock);
+
+	/*
+	 * If finalize failed in EL1 driver for any reason, this means we can't trust the DMA
+	 * isolation. So we have to inform pKVM to properly protect itself.
+	 */
+	if (!ret && err)
+		pkvm_handle_system_misconfiguration(NO_DMA_ISOLATION);
+
 	return ret;
 }
 

arch/arm64/kvm/iommu.c

@@ -58,8 +58,8 @@ int pkvm_iommu_resume(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(pkvm_iommu_resume);
 
-int pkvm_iommu_finalize(void)
+int pkvm_iommu_finalize(int err)
 {
-	return kvm_call_hyp_nvhe(__pkvm_iommu_finalize);
+	return kvm_call_hyp_nvhe(__pkvm_iommu_finalize, err);
 }
 EXPORT_SYMBOL_GPL(pkvm_iommu_finalize);