[Qemu-devel] [PATCH 4/4] hw/ppc/spapr: Implement the h_page_init hypercall

[Thomas Huth <thuth@redhat.com>]

This hypercall either initializes a page with zeros, or copies
another page.
According to LoPAPR, the i-cache of the page should also be
flushed when using H_ICACHE_INVALIDATE or H_ICACHE_SYNCHRONIZE,
but this is currently only done when running with TCG - assuming
the cache will be flushed with KVM anyway when switching back to
kernel / VM context.
The code currently also does not explicitely flush the data cache
with H_ICACHE_SYNCHRONIZE, since this either also should be done
when switching back to kernel / VM context (with KVM), or not matter
anyway (for TCG).

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hw/ppc/spapr_hcall.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index f14f849..91e703d 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -387,6 +387,47 @@ static target_ulong h_set_xdabr(PowerPCCPU *cpu, sPAPRMachineState *spapr,
     return H_SUCCESS;
 }
 
+static target_ulong h_page_init(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                                target_ulong opcode, target_ulong *args)
+{
+    target_ulong flags = args[0];
+    target_ulong dest = args[1];
+    target_ulong src = args[2];
+    uint8_t buf[TARGET_PAGE_SIZE];
+
+    if (flags & ~(H_ICACHE_SYNCHRONIZE | H_ICACHE_INVALIDATE
+                  | H_COPY_PAGE | H_ZERO_PAGE)) {
+        qemu_log_mask(LOG_UNIMP, "h_page_init: Bad flags (" TARGET_FMT_lx "\n",
+                      flags);
+    }
+
+    if (!is_ram_address(spapr, dest) || (dest & ~TARGET_PAGE_MASK) != 0) {
+        return H_PARAMETER;
+    }
+
+    if (flags & H_COPY_PAGE) {
+        if (!is_ram_address(spapr, src) || (src & ~TARGET_PAGE_MASK) != 0) {
+            return H_PARAMETER;
+        }
+        cpu_physical_memory_read(src, buf, TARGET_PAGE_SIZE);
+    } else if (flags & H_ZERO_PAGE) {
+        memset(buf, 0, TARGET_PAGE_SIZE);
+    }
+
+    if (flags & (H_COPY_PAGE | H_ZERO_PAGE)) {
+        cpu_physical_memory_write(dest, buf, TARGET_PAGE_SIZE);
+    }
+
+    if (flags & (H_ICACHE_SYNCHRONIZE | H_ICACHE_INVALIDATE)) {
+        if (tcg_enabled()) {
+            tb_flush(CPU(cpu));
+        }
+        /* XXX: Flush data cache for H_ICACHE_SYNCHRONIZE? */
+    }
+
+    return H_SUCCESS;
+}
+
 #define FLAGS_REGISTER_VPA         0x0000200000000000ULL
 #define FLAGS_REGISTER_DTL         0x0000400000000000ULL
 #define FLAGS_REGISTER_SLBSHADOW   0x0000600000000000ULL
@@ -1046,6 +1087,7 @@ static void hypercall_register_types(void)
     spapr_register_hypercall(H_SET_SPRG0, h_set_sprg0);
     spapr_register_hypercall(H_SET_DABR, h_set_dabr);
     spapr_register_hypercall(H_SET_XDABR, h_set_xdabr);
+    spapr_register_hypercall(H_PAGE_INIT, h_page_init);
     spapr_register_hypercall(H_SET_MODE, h_set_mode);
 
     /* "debugger" hcalls (also used by SLOF). Note: We do -not- differenciate
-- 
1.8.3.1