From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
Wei Liu <wl@xen.org>, Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [Xen-devel] [PATCH 5/9] x86/HVM: refuse CR3 loads with reserved (upper) bits set
Date: Thu, 12 Sep 2019 13:45:02 +0200 [thread overview]
Message-ID: <20190912114502.ietnlugtxmazfgzi@Air-de-Roger> (raw)
In-Reply-To: <30619001-ca6c-0450-a0bb-4d71687b281a@suse.com>
On Wed, Sep 11, 2019 at 05:24:41PM +0200, Jan Beulich wrote:
> While bits 11 and below are, if not used for other purposes, reserved
> but ignored, bits beyond physical address width are supposed to raise
> exceptions (at least in the non-nested case; I'm not convinced the
> current nested SVM/VMX behavior of raising #GP(0) here is correct, but
> that's not the subject of this change).
>
> Introduce currd as a local variable, and replace other v->domain
> instances at the same time.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
LGTM, just two comments which are not related to functionality, so:
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
>
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -1004,6 +1004,13 @@ static int hvm_load_cpu_ctxt(struct doma
> return -EINVAL;
> }
>
> + if ( ctxt.cr3 & ~((1UL << d->arch.cpuid->extd.maxphysaddr) - 1) )
> + {
> + printk(XENLOG_G_ERR "HVM%d restore: bad CR3 %#" PRIx64 "\n",
gprintk would be more natural here IMO.
> + d->domain_id, ctxt.cr3);
> + return X86EMUL_EXCEPTION;
> + }
> +
> if ( (ctxt.flags & ~XEN_X86_FPU_INITIALISED) != 0 )
> {
> gprintk(XENLOG_ERR, "bad flags value in CPU context: %#x\n",
> @@ -2290,10 +2297,19 @@ int hvm_set_cr0(unsigned long value, boo
> int hvm_set_cr3(unsigned long value, bool noflush, bool may_defer)
> {
> struct vcpu *v = current;
> + struct domain *currd = v->domain;
> struct page_info *page;
> unsigned long old = v->arch.hvm.guest_cr[3];
>
> - if ( may_defer && unlikely(v->domain->arch.monitor.write_ctrlreg_enabled &
> + if ( value & ~((1UL << currd->arch.cpuid->extd.maxphysaddr) - 1) )
I would consider introducing a macro/inline helper for this, since
it's already used twice in this patch.
Thanks, Roger.
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next prev parent reply other threads:[~2019-09-12 11:45 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-11 15:15 [Xen-devel] [PATCH RESEND/PING 0/9] XSA-292 follow-up Jan Beulich
2019-09-11 15:21 ` [Xen-devel] [PATCH 1/9] x86: adjust cr3_pcid() return type Jan Beulich
2019-09-12 9:19 ` Roger Pau Monné
2019-09-11 15:22 ` [Xen-devel] [PATCH 2/9] x86: limit the amount of TLB flushing in switch_cr3_cr4() Jan Beulich
2019-09-12 9:54 ` Roger Pau Monné
2019-09-12 10:11 ` Jan Beulich
2019-09-12 10:38 ` Roger Pau Monné
2019-09-11 15:22 ` [Xen-devel] [PATCH 3/9] x86/mm: honor opt_pcid also for 32-bit PV domains Jan Beulich
2019-09-12 10:34 ` Roger Pau Monné
2019-09-12 10:45 ` Jan Beulich
2019-09-11 15:23 ` [Xen-devel] [PATCH 4/9] x86/HVM: move NOFLUSH handling out of hvm_set_cr3() Jan Beulich
2019-09-12 11:35 ` Roger Pau Monné
2019-09-12 11:52 ` Jan Beulich
2019-09-12 14:44 ` Roger Pau Monné
2019-09-12 14:47 ` Jan Beulich
2019-09-12 15:42 ` Roger Pau Monné
2019-09-12 15:52 ` Jan Beulich
2019-09-11 15:24 ` [Xen-devel] [PATCH 5/9] x86/HVM: refuse CR3 loads with reserved (upper) bits set Jan Beulich
2019-09-12 11:45 ` Roger Pau Monné [this message]
2019-09-12 12:01 ` Jan Beulich
2019-09-11 15:25 ` [Xen-devel] [PATCH 6/9] x86/HVM: relax shadow mode check in hvm_set_cr3() Jan Beulich
2019-09-12 14:50 ` Roger Pau Monné
2019-09-11 15:25 ` [Xen-devel] [PATCH 7/9] x86/HVM: cosmetics to hvm_set_cr3() Jan Beulich
2019-09-12 15:04 ` Roger Pau Monné
2019-09-11 15:26 ` [Xen-devel] [PATCH 8/9] x86/CPUID: drop INVPCID dependency on PCID Jan Beulich
2019-09-12 15:11 ` Roger Pau Monné
2019-09-11 15:26 ` [Xen-devel] [PATCH 9/9] x86: PCID is unused when !PV Jan Beulich
2019-09-12 15:31 ` Roger Pau Monné
2019-09-12 15:46 ` Jan Beulich
2019-09-12 15:48 ` Jan Beulich
2019-09-12 15:57 ` Roger Pau Monné
-- strict thread matches above, loose matches on Subject: below --
2019-05-02 11:35 [PATCH 0/9] XSA-292 follow-up Jan Beulich
2019-05-02 12:20 ` [PATCH 5/9] x86/HVM: refuse CR3 loads with reserved (upper) bits set Jan Beulich
2019-05-02 12:20 ` [Xen-devel] " Jan Beulich
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