Merge branch 'for-6.7/config_pm' into for-linus

- #ifdef CONFIG_PM removal from HID code (Thomas Weißschuh)

1 files changed, 30 insertions, 6 deletions

diff --git a/tools/testing/selftests/kvm/lib/x86_64/ucall.c b/tools/testing/selftests/kvm/lib/x86_64/ucall.c
index 4d41dc63cc9e..1265cecc7dd1 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/ucall.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/ucall.c
@@ -8,14 +8,38 @@
 
 #define UCALL_PIO_PORT ((uint16_t)0x1000)
 
-void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
-{
-}
-
 void ucall_arch_do_ucall(vm_vaddr_t uc)
 {
-	asm volatile("in %[port], %%al"
-		: : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory");
+	/*
+	 * FIXME: Revert this hack (the entire commit that added it) once nVMX
+	 * preserves L2 GPRs across a nested VM-Exit.  If a ucall from L2, e.g.
+	 * to do a GUEST_SYNC(), lands the vCPU in L1, any and all GPRs can be
+	 * clobbered by L1.  Save and restore non-volatile GPRs (clobbering RBP
+	 * in particular is problematic) along with RDX and RDI (which are
+	 * inputs), and clobber volatile GPRs. *sigh*
+	 */
+#define HORRIFIC_L2_UCALL_CLOBBER_HACK	\
+	"rcx", "rsi", "r8", "r9", "r10", "r11"
+
+	asm volatile("push %%rbp\n\t"
+		     "push %%r15\n\t"
+		     "push %%r14\n\t"
+		     "push %%r13\n\t"
+		     "push %%r12\n\t"
+		     "push %%rbx\n\t"
+		     "push %%rdx\n\t"
+		     "push %%rdi\n\t"
+		     "in %[port], %%al\n\t"
+		     "pop %%rdi\n\t"
+		     "pop %%rdx\n\t"
+		     "pop %%rbx\n\t"
+		     "pop %%r12\n\t"
+		     "pop %%r13\n\t"
+		     "pop %%r14\n\t"
+		     "pop %%r15\n\t"
+		     "pop %%rbp\n\t"
+		: : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory",
+		     HORRIFIC_L2_UCALL_CLOBBER_HACK);
 }
 
 void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)