[PATCH kvmtool 15/15] arm/arm64: Validate firmware address in kvm__arch_validate_cfg()

[Alexandru Elisei]

We know at user configuration time if the firmware address is outside
RAM, validate the address in kvm__arch_validate_cfg() before creating
the VM.

Signed-off-by: Alexandru Elisei <alexandru.elisei at arm.com>
---
 arm/kvm.c | 36 ++++++++++++++----------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/arm/kvm.c b/arm/kvm.c
index 3edc6fdbcb5f..79d085ab9965 100644
--- a/arm/kvm.c
+++ b/arm/kvm.c
@@ -33,8 +33,20 @@ int fw_addr_parser(const struct option *opt, const char *arg, int unset)
 
 void kvm__arch_validate_cfg(struct kvm *kvm)
 {
-	if (kvm->cfg.arch.fw_addr && !kvm->cfg.firmware_filename)
-		die("--firmware-address is only valid when loading a firmware image");
+	u64 fw_addr = kvm->cfg.arch.fw_addr;
+	u64 ram_addr = kvm->cfg.ram_addr;
+	u64 ram_size = kvm->cfg.ram_size;
+
+	if (fw_addr) {
+		if (!kvm->cfg.firmware_filename)
+			die("--firmware-address is only valid when loading a firmware image");
+
+		if (fw_addr < ram_addr || fw_addr >= ram_addr + ram_size) {
+			die("Firmware address 0x%016llx outside guest memory: "
+			    "0x%016llx - 0x%016llx",
+			    fw_addr, ram_addr, ram_addr + ram_size);
+		}
+	}
 
 	kvm__arm_validate_cfg(kvm);
 }
@@ -196,23 +208,6 @@ bool kvm__arch_load_kernel_image(struct kvm *kvm, int fd_kernel, int fd_initrd,
 	return true;
 }
 
-static bool validate_fw_addr(struct kvm *kvm, u64 fw_addr)
-{
-	u64 ram_phys;
-
-	ram_phys = host_to_guest_flat(kvm, kvm->ram_start);
-
-	if (fw_addr < ram_phys || fw_addr >= ram_phys + kvm->ram_size) {
-		pr_err("Provide --firmware-address an address in RAM: "
-		       "0x%016llx - 0x%016llx",
-		       ram_phys, ram_phys + kvm->ram_size);
-
-		return false;
-	}
-
-	return true;
-}
-
 bool kvm__load_firmware(struct kvm *kvm, const char *firmware_filename)
 {
 	u64 fw_addr = kvm->cfg.arch.fw_addr;
@@ -227,9 +222,6 @@ bool kvm__load_firmware(struct kvm *kvm, const char *firmware_filename)
 	if (fw_addr == 0)
 		fw_addr = kvm->arch.memory_guest_start;
 
-	if (!validate_fw_addr(kvm, fw_addr))
-		die("Bad firmware destination: 0x%016llx", fw_addr);
-
 	fd = open(firmware_filename, O_RDONLY);
 	if (fd < 0)
 		return false;
-- 
2.36.0