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From:   Claudio Imbrenda <imbrenda@linux.ibm.com>
To:     linux-kernel@vger.kernel.org
Cc:     kvm@vger.kernel.org, linux-s390@vger.kernel.org,
        frankja@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com,
        david@redhat.com, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Uladzislau Rezki <urezki@gmail.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        David Rientjes <rientjes@google.com>
Subject: [PATCH v2 2/2] KVM: s390: fix for hugepage vmalloc
Date:   Tue,  8 Jun 2021 20:06:18 +0200
Message-Id: <20210608180618.477766-3-imbrenda@linux.ibm.com>
In-Reply-To: <20210608180618.477766-1-imbrenda@linux.ibm.com>
References: <20210608180618.477766-1-imbrenda@linux.ibm.com>
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The Create Secure Configuration Ultravisor Call does not support using
large pages for the virtual memory area. This is a hardware limitation.

This patch replaces the vzalloc call with a longer but equivalent
__vmalloc_node_range call, also setting the VM_NO_HUGE_VMAP flag, to
guarantee that this allocation will not be performed with large pages.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: 121e6f3258fe393e22c3 ("mm/vmalloc: hugepage vmalloc mappings")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: David Rientjes <rientjes@google.com>
---
 arch/s390/kvm/pv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 813b6e93dc83..6087fe7ae77c 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -140,7 +140,10 @@ static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
 	/* Allocate variable storage */
 	vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
 	vlen += uv_info.guest_virt_base_stor_len;
-	kvm->arch.pv.stor_var = vzalloc(vlen);
+	kvm->arch.pv.stor_var = __vmalloc_node_range(vlen, PAGE_SIZE, VMALLOC_START, VMALLOC_END,
+						     GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
+						     VM_NO_HUGE_VMAP, NUMA_NO_NODE,
+						     __builtin_return_address(0));
 	if (!kvm->arch.pv.stor_var)
 		goto out_err;
 	return 0;
-- 
2.31.1