s390/protvirt: add ultravisor initialization

Before being able to host protected virtual machines, donate some of
the memory to the ultravisor. Besides that the ultravisor might impose
addressing limitations for memory used to back protected VM storage. Treat
that limit as protected virtualization host's virtual memory limit.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

2 files changed, 53 insertions, 0 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index a2496382175e..1423090a2259 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -560,6 +560,9 @@ static void __init setup_memory_end(void)
 			vmax = _REGION1_SIZE; /* 4-level kernel page table */
 	}
 
+	if (is_prot_virt_host())
+		adjust_to_uv_max(&vmax);
+
 	/* module area is at the end of the kernel address space. */
 	MODULES_END = vmax;
 	MODULES_VADDR = MODULES_END - MODULES_LEN;
@@ -1134,6 +1137,8 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));
 
+	if (is_prot_virt_host())
+		setup_uv();
 	setup_memory_end();
 	setup_memory();
 	dma_contiguous_reserve(memory_end);
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index b1f936710360..1ddc42154ef6 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -49,4 +49,52 @@ static int __init prot_virt_setup(char *val)
 	return rc;
 }
 early_param("prot_virt", prot_virt_setup);
+
+static int __init uv_init(unsigned long stor_base, unsigned long stor_len)
+{
+	struct uv_cb_init uvcb = {
+		.header.cmd = UVC_CMD_INIT_UV,
+		.header.len = sizeof(uvcb),
+		.stor_origin = stor_base,
+		.stor_len = stor_len,
+	};
+
+	if (uv_call(0, (uint64_t)&uvcb)) {
+		pr_err("Ultravisor init failed with rc: 0x%x rrc: 0%x\n",
+		       uvcb.header.rc, uvcb.header.rrc);
+		return -1;
+	}
+	return 0;
+}
+
+void __init setup_uv(void)
+{
+	unsigned long uv_stor_base;
+
+	uv_stor_base = (unsigned long)memblock_alloc_try_nid(
+		uv_info.uv_base_stor_len, SZ_1M, SZ_2G,
+		MEMBLOCK_ALLOC_ACCESSIBLE, NUMA_NO_NODE);
+	if (!uv_stor_base) {
+		pr_warn("Failed to reserve %lu bytes for ultravisor base storage\n",
+			uv_info.uv_base_stor_len);
+		goto fail;
+	}
+
+	if (uv_init(uv_stor_base, uv_info.uv_base_stor_len)) {
+		memblock_free(uv_stor_base, uv_info.uv_base_stor_len);
+		goto fail;
+	}
+
+	pr_info("Reserving %luMB as ultravisor base storage\n",
+		uv_info.uv_base_stor_len >> 20);
+	return;
+fail:
+	pr_info("Disabling support for protected virtualization");
+	prot_virt_host = 0;
+}
+
+void adjust_to_uv_max(unsigned long *vmax)
+{
+	*vmax = min_t(unsigned long, *vmax, uv_info.max_sec_stor_addr);
+}
 #endif