From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Tom Lendacky <thomas.lendacky@amd.com>,
Borislav Petkov <bp@suse.de>,
Brijesh Singh <brijesh.singh@amd.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 03/13] KVM: SVM: Move SEV module params/variables to sev.c
Date: Mon, 11 Jan 2021 11:42:48 +0100 [thread overview]
Message-ID: <87sg7792l3.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20210109004714.1341275-4-seanjc@google.com>
Sean Christopherson <seanjc@google.com> writes:
> Unconditionally invoke sev_hardware_setup() when configuring SVM and
> handle clearing the module params/variable 'sev' and 'sev_es' in
> sev_hardware_setup(). This allows making said variables static within
> sev.c and reduces the odds of a collision with guest code, e.g. the guest
> side of things has already laid claim to 'sev_enabled'.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/x86/kvm/svm/sev.c | 11 +++++++++++
> arch/x86/kvm/svm/svm.c | 15 +--------------
> arch/x86/kvm/svm/svm.h | 2 --
> 3 files changed, 12 insertions(+), 16 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 0eeb6e1b803d..8ba93b8fa435 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -27,6 +27,14 @@
>
> #define __ex(x) __kvm_handle_fault_on_reboot(x)
>
> +/* enable/disable SEV support */
> +static int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
> +module_param(sev, int, 0444);
> +
> +/* enable/disable SEV-ES support */
> +static int sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
> +module_param(sev_es, int, 0444);
Two stupid questions (and not really related to your patch) for
self-eduacation if I may:
1) Why do we rely on CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT (which
sound like it control the guest side of things) to set defaults here?
2) It appears to be possible to do 'modprobe kvm_amd sev=0 sev_es=1' and
this looks like a bogus configuration, should we make an effort to
validate the correctness upon module load?
> +
> static u8 sev_enc_bit;
> static int sev_flush_asids(void);
> static DECLARE_RWSEM(sev_deactivate_lock);
> @@ -1249,6 +1257,9 @@ void __init sev_hardware_setup(void)
> bool sev_es_supported = false;
> bool sev_supported = false;
>
> + if (!IS_ENABLED(CONFIG_KVM_AMD_SEV) || !sev)
> + goto out;
> +
> /* Does the CPU support SEV? */
> if (!boot_cpu_has(X86_FEATURE_SEV))
> goto out;
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index ccf52c5531fb..f89f702b2a58 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -189,14 +189,6 @@ module_param(vls, int, 0444);
> static int vgif = true;
> module_param(vgif, int, 0444);
>
> -/* enable/disable SEV support */
> -int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
> -module_param(sev, int, 0444);
> -
> -/* enable/disable SEV-ES support */
> -int sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
> -module_param(sev_es, int, 0444);
> -
> bool __read_mostly dump_invalid_vmcb;
> module_param(dump_invalid_vmcb, bool, 0644);
>
> @@ -976,12 +968,7 @@ static __init int svm_hardware_setup(void)
> kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
> }
>
> - if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev) {
> - sev_hardware_setup();
> - } else {
> - sev = false;
> - sev_es = false;
> - }
> + sev_hardware_setup();
>
> svm_adjust_mmio_mask();
>
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index 0fe874ae5498..8e169835f52a 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -408,8 +408,6 @@ static inline bool gif_set(struct vcpu_svm *svm)
> #define MSR_CR3_LONG_MBZ_MASK 0xfff0000000000000U
> #define MSR_INVALID 0xffffffffU
>
> -extern int sev;
> -extern int sev_es;
> extern bool dump_invalid_vmcb;
>
> u32 svm_msrpm_offset(u32 msr);
--
Vitaly
next prev parent reply other threads:[~2021-01-11 10:44 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-09 0:47 [PATCH 00/13] KVM: SVM: Misc SEV cleanups Sean Christopherson
2021-01-09 0:47 ` [PATCH 01/13] KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails Sean Christopherson
2021-01-11 14:42 ` Tom Lendacky
2021-01-11 18:07 ` Sean Christopherson
2021-01-09 0:47 ` [PATCH 02/13] KVM: SVM: Zero out the VMCB array used to track SEV ASID association Sean Christopherson
2021-01-09 0:47 ` [PATCH 03/13] KVM: SVM: Move SEV module params/variables to sev.c Sean Christopherson
2021-01-11 10:42 ` Vitaly Kuznetsov [this message]
2021-01-11 15:36 ` Tom Lendacky
2021-01-11 16:58 ` Vitaly Kuznetsov
2021-01-12 22:18 ` Sean Christopherson
2021-01-11 15:30 ` Tom Lendacky
2021-01-09 0:47 ` [PATCH 04/13] x86/cpufeatures: Assign dedicated feature word for AMD mem encryption Sean Christopherson
2021-01-09 0:47 ` [PATCH 05/13] KVM: x86: Override reported SME/SEV feature flags with host mask Sean Christopherson
2021-01-09 0:47 ` [PATCH 06/13] x86/sev: Rename global "sev_enabled" flag to "sev_guest" Sean Christopherson
2021-01-11 16:02 ` Tom Lendacky
2021-01-11 16:47 ` Tom Lendacky
2021-01-11 17:58 ` Sean Christopherson
2021-01-11 20:28 ` Sean Christopherson
2021-01-09 0:47 ` [PATCH 07/13] KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables Sean Christopherson
2021-01-11 16:03 ` Tom Lendacky
2021-01-09 0:47 ` [PATCH 08/13] KVM: SVM: Unconditionally invoke sev_hardware_teardown() Sean Christopherson
2021-01-09 0:47 ` [PATCH 09/13] KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() Sean Christopherson
2021-01-09 0:47 ` [PATCH 10/13] KVM: SVM: Move SEV VMCB tracking allocation to sev.c Sean Christopherson
2021-01-09 0:47 ` [PATCH 11/13] KVM: SVM: Drop redundant svm_sev_enabled() helper Sean Christopherson
2021-01-11 17:57 ` Tom Lendacky
2021-01-11 20:59 ` Sean Christopherson
2021-01-09 0:47 ` [PATCH 12/13] KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() Sean Christopherson
2021-01-09 0:47 ` [PATCH 13/13] KVM: SVM: Skip SEV cache flush if no ASIDs have been used Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87sg7792l3.fsf@vitty.brq.redhat.com \
--to=vkuznets@redhat.com \
--cc=bp@suse.de \
--cc=brijesh.singh@amd.com \
--cc=dave.hansen@linux.intel.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=seanjc@google.com \
--cc=thomas.lendacky@amd.com \
--cc=wanpengli@tencent.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).