From f7134d8cbfb8fa42f3e4970f75ab0b0a7a11596e Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Fri, 13 Apr 2018 15:42:34 +0000 Subject: [PATCH] x86/msr: Virtualise MSR_SPEC_CTRL.SSBD for guests to use Almost all infrastructure is already in place. Update the reserved bits calculation in guest_wrmsr(). Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- xen/arch/x86/domctl.c | 3 ++- xen/arch/x86/hvm/hvm.c | 3 ++- xen/arch/x86/traps.c | 3 ++- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c index 90fe100..0357d62 100644 --- a/xen/arch/x86/domctl.c +++ b/xen/arch/x86/domctl.c @@ -1136,7 +1136,8 @@ long arch_do_domctl( * ignored) when STIBP isn't enumerated in hardware. */ - if ( msr.value & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP) ) + if ( msr.value & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | + (boot_cpu_has(X86_FEATURE_SSBD) ? SPEC_CTRL_SSBD : 0)) ) break; v->arch.spec_ctrl = msr.value; continue; diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 67f75b9..b5b72d0 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -4997,7 +4997,8 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content, * when STIBP isn't enumerated in hardware. */ - if ( msr_content & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP) ) + if ( msr_content & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | + ((edx & cpufeat_mask(X86_FEATURE_SSBD) ? SPEC_CTRL_SSBD : 0))) ) goto gp_fault; /* Rsvd bit set? */ v->arch.spec_ctrl = msr_content; diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c index 75d41b1..eeac17b 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -2744,7 +2744,8 @@ static int emulate_privileged_op(struct cpu_user_regs *regs) * when STIBP isn't enumerated in hardware. */ - if ( msr_content & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP) ) + if ( msr_content & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | + ((edx & cpufeat_mask(X86_FEATURE_SSBD) ? SPEC_CTRL_SSBD : 0))) ) goto fail; /* Rsvd bit set? */ v->arch.spec_ctrl = eax; -- 2.1.4