[RFC,15/16] kvm tools: provide a mechanism for translating host to guest addresses

Commit Message

Will Deacon Nov. 12, 2012, 11:57 a.m. UTC

When generating a device tree for a guest, it is useful to have a helper
for converting host addresses to guest addresses in order to populate
the device nodes correctly.

This patch adds such a helper, following a similar implementation to the
reverse translation function that already exists.

Signed-off-by: Will Deacon <[e-mail]>
---
 tools/kvm/include/kvm/kvm.h |    1 +
 tools/kvm/kvm.c             |   16 ++++++++++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)

Patch

diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
index ce09142..3ebd229 100644
--- a/tools/kvm/include/kvm/kvm.h
+++ b/tools/kvm/include/kvm/kvm.h
@@ -106,6 +106,7 @@  bool kvm__arch_cpu_supports_vm(void);
 void kvm__arch_periodic_poll(struct kvm *kvm);
 
 void *guest_flat_to_host(struct kvm *kvm, unsigned long offset);
+unsigned long host_to_guest_flat(struct kvm *kvm, void *ptr);
 
 int load_flat_binary(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline);
 bool load_bzimage(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline, u16 vidmode);
diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
index 1702533..b876906 100644
--- a/tools/kvm/kvm.c
+++ b/tools/kvm/kvm.c
@@ -200,6 +200,22 @@  void *guest_flat_to_host(struct kvm *kvm, unsigned long offset)
 	return NULL;
 }
 
+unsigned long host_to_guest_flat(struct kvm *kvm, void *ptr)
+{
+	struct kvm_mem_bank *bank;
+
+	list_for_each_entry(bank, &kvm->mem_banks, list) {
+		void *bank_start = bank->host_addr;
+		void *bank_end = bank_start + bank->size;
+
+		if (ptr >= bank_start && ptr < bank_end)
+			return bank->guest_phys_addr + (ptr - bank_start);
+	}
+
+	pr_warning("unable to translate host address %p to guest", ptr);
+	return 0;
+}
+
 int kvm__recommended_cpus(struct kvm *kvm)
 {
 	int ret;