On Mon, Mar 11, 2024 at 11:35:38AM -0700, Pawan Gupta wrote: > On Mon, Mar 04, 2024 at 09:01:52PM -0800, Pawan Gupta wrote: > > This is the backport of recently upstreamed series that moves VERW > > execution to a later point in exit-to-user path. This is needed because > > in some cases it may be possible for data accessed after VERW executions > > may end into MDS affected CPU buffers. Moving VERW closer to ring > > transition reduces the attack surface. > > > > - The series includes a dependency commit f87bc8dc7a7c ("x86/asm: Add > > _ASM_RIP() macro for x86-64 (%rip) suffix"). > > > > - Patch 2 includes a change that adds runtime patching for jmp (instead > > of verw in original series) due to lack of rip-relative relocation > > support in kernels <v6.5. > > > > - Fixed warning: > > arch/x86/entry/entry.o: warning: objtool: mds_verw_sel+0x0: unreachable instruction. > > > > - Resolved merge conflicts in: > > swapgs_restore_regs_and_return_to_usermode in entry_64.S. > > __vmx_vcpu_run in vmenter.S. > > vmx_update_fb_clear_dis in vmx.c. > > > > - Boot tested with KASLR and KPTI enabled. > > > > - Verified VERW being executed with mitigation ON, and not being > > executed with mitigation turned OFF. > > > > To: stable@xxxxxxxxxxxxxxx > > > > Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx> > > --- > > H. Peter Anvin (Intel) (1): > > x86/asm: Add _ASM_RIP() macro for x86-64 (%rip) suffix > > > > Pawan Gupta (5): > > x86/bugs: Add asm helpers for executing VERW > > x86/entry_64: Add VERW just before userspace transition > > x86/entry_32: Add VERW just before userspace transition > > x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key > > KVM/VMX: Move VERW closer to VMentry for MDS mitigation > > > > Sean Christopherson (1): > > KVM/VMX: Use BT+JNC, i.e. EFLAGS.CF to select VMRESUME vs. VMLAUNCH [Resending this. Sorry, last time my mutt aliases didn't resolve correctly for some reason.] Could this and below backports be queue up? 5.10.y https://lore.kernel.org/stable/20240305-delay-verw-backport-5-10-y-v1-0-50bf452e96ba@xxxxxxxxxxxxxxx/ 5.4.y https://lore.kernel.org/stable/20240226122237.198921-1-nik.borisov@xxxxxxxx/ Just FYI.. this series is already in stable trees for 6.1, 6.6, 6.7.