From: Jan Beulich Date: Tue, 11 Oct 2022 12:30:41 +0000 (+0200) Subject: x86emul: respect NSCB X-Git-Tag: archive/raspbian/4.17.0-1+rpi1^2~33^2~142 X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=87a20c98d9f0f422727fe9b4b9e22c2c43a5cd9c;p=xen.git x86emul: respect NSCB protmode_load_seg() would better adhere to that "feature" of clearing base (and limit) during NULL selector loads. Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper Release-acked-by: Henry Wang --- diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c index f6778dd493..e38f98b547 100644 --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -1970,6 +1970,7 @@ amd_like(const struct x86_emulate_ctxt *ctxt) #define vcpu_has_tbm() (ctxt->cpuid->extd.tbm) #define vcpu_has_clzero() (ctxt->cpuid->extd.clzero) #define vcpu_has_wbnoinvd() (ctxt->cpuid->extd.wbnoinvd) +#define vcpu_has_nscb() (ctxt->cpuid->extd.nscb) #define vcpu_has_bmi1() (ctxt->cpuid->feat.bmi1) #define vcpu_has_hle() (ctxt->cpuid->feat.hle) @@ -2102,7 +2103,7 @@ protmode_load_seg( case x86_seg_tr: goto raise_exn; } - if ( !_amd_like(cp) || !ops->read_segment || + if ( !_amd_like(cp) || vcpu_has_nscb() || !ops->read_segment || ops->read_segment(seg, sreg, ctxt) != X86EMUL_OKAY ) memset(sreg, 0, sizeof(*sreg)); else