Sean Christopherson 842f4be958 KVM: VMX: Add a trampoline to fix VMREAD error handling ... Add a hand coded assembly trampoline to preserve volatile registers across vmread_error(), and to handle the calling convention differences between 64-bit and 32-bit due to asmlinkage on vmread_error(). Pass @field and @fault on the stack when invoking the trampoline to avoid clobbering volatile registers in the context of the inline assembly. Calling vmread_error() directly from inline assembly is partially broken on 64-bit, and completely broken on 32-bit. On 64-bit, it will clobber %rdi and %rsi (used to pass @field and @fault) and any volatile regs written by vmread_error(). On 32-bit, asmlinkage means vmread_error() expects the parameters to be passed on the stack, not via regs. Opportunistically zero out the result in the trampoline to save a few bytes of code for every VMREAD. A happy side effect of the trampoline is that the inline code footprint is reduced by three bytes on 64-bit due to PUSH/POP being more efficent (in terms of opcode bytes) than MOV. Fixes: 6e2020977e ("KVM: VMX: Add error handling to VMREAD helper") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200326160712.28803-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2020-03-31 10:48:11 -04:00
..
capabilities.h	KVM: x86: Handle PKU CPUID adjustment in VMX code	2020-03-16 17:58:19 +01:00
evmcs.c	x86/kvm/hyper-v: don't allow to turn on unsupported VMX controls for nested guests	2020-02-05 15:55:26 +01:00
evmcs.h	KVM: nVMX: properly handle errors in nested_vmx_handle_enlightened_vmptrld()	2020-03-16 18:19:30 +01:00
nested.c	KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection	2020-03-31 10:48:08 -04:00
nested.h	KVM: VMX: Configure runtime hooks using vmx_x86_ops	2020-03-31 10:48:06 -04:00
ops.h	KVM: VMX: Add a trampoline to fix VMREAD error handling	2020-03-31 10:48:11 -04:00
pmu_intel.c	KVM: VMX: Directly query Intel PT mode when refreshing PMUs	2020-03-16 17:58:38 +01:00
vmcs12.c
vmcs12.h	KVM/arm updates for 5.3	2019-07-11 15:14:16 +02:00
vmcs_shadow_fields.h	KVM: Fix some out-dated function names in comment	2020-01-21 13:57:27 +01:00
vmcs.h	KVM: VMX: Leave preemption timer running when it's disabled	2019-06-18 17:10:46 +02:00
vmenter.S	KVM: VMX: Add a trampoline to fix VMREAD error handling	2020-03-31 10:48:11 -04:00
vmx.c	KVM: VMX: Annotate vmx_x86_ops as __initdata	2020-03-31 10:48:10 -04:00
vmx.h	KVM: VMX: Fold loaded_vmcs_init() into alloc_loaded_vmcs()	2020-03-23 15:44:26 -04:00