diff mbox series

[v7,19/19] hvf: arm: Handle Windows 10 SMC call

Message ID 20210516195855.28869-20-agraf@csgraf.de (mailing list archive)
State New, archived
Headers show
Series hvf: Implement Apple Silicon Support | expand

Commit Message

Alexander Graf May 16, 2021, 7:58 p.m. UTC 
Windows 10 calls an SMCCC call via SMC unconditionally on boot. It lives
in the trusted application call number space, but its purpose is unknown.

In our current SMC implementation, we inject a UDEF for unknown SMC calls,
including this one. However, Windows breaks on boot when we do this. Instead,
let's return an error code.

With this patch applied I can successfully boot the current Windows 10
Insider Preview in HVF.

Signed-off-by: Alexander Graf <agraf@csgraf.de>
---
 target/arm/hvf/hvf.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index acf8fd4060..12dd5bbb0c 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -928,6 +928,10 @@  int hvf_vcpu_exec(CPUState *cpu)
         cpu_synchronize_state(cpu);
         if (!hvf_handle_psci_call(cpu)) {
             advance_pc = true;
+        } else if (env->xregs[0] == QEMU_SMCCC_TC_WINDOWS10_BOOT) {
+            /* This special SMC is called by Windows 10 on boot. Return error. */
+            env->xregs[0] = -1;
+            advance_pc = true;
         } else {
             trace_hvf_unknown_smc(env->xregs[0]);
             hvf_raise_exception(env, EXCP_UDEF, syn_uncategorized());