* [PATCH MANUALSEL 5.10 2/4] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled
[not found] <20211213142020.352376-1-sashal@kernel.org>
@ 2021-12-13 14:20 ` Sasha Levin
2021-12-13 14:29 ` Paolo Bonzini
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE Sasha Levin
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE Sasha Levin
2 siblings, 1 reply; 6+ messages in thread
From: Sasha Levin @ 2021-12-13 14:20 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Paolo Bonzini, Sasha Levin, tglx, mingo, bp, dave.hansen, x86,
kvm
From: Paolo Bonzini <pbonzini@redhat.com>
[ Upstream commit e90e51d5f01d2baae5dcce280866bbb96816e978 ]
There is nothing to synchronize if APICv is disabled, since neither
other vCPUs nor assigned devices can set PIR.ON.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/vmx/vmx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5b7664d51dc2b..dff8ab5a53280 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7814,10 +7814,10 @@ static __init int hardware_setup(void)
ple_window_shrink = 0;
}
- if (!cpu_has_vmx_apicv()) {
+ if (!cpu_has_vmx_apicv())
enable_apicv = 0;
+ if (!enable_apicv)
vmx_x86_ops.sync_pir_to_irr = NULL;
- }
if (cpu_has_vmx_tsc_scaling()) {
kvm_has_tsc_control = true;
--
2.33.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH MANUALSEL 5.10 2/4] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 2/4] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled Sasha Levin
@ 2021-12-13 14:29 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2021-12-13 14:29 UTC (permalink / raw)
To: Sasha Levin, linux-kernel, stable; +Cc: tglx, mingo, bp, dave.hansen, x86, kvm
On 12/13/21 15:20, Sasha Levin wrote:
> From: Paolo Bonzini <pbonzini@redhat.com>
>
> [ Upstream commit e90e51d5f01d2baae5dcce280866bbb96816e978 ]
>
> There is nothing to synchronize if APICv is disabled, since neither
> other vCPUs nor assigned devices can set PIR.ON.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> arch/x86/kvm/vmx/vmx.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 5b7664d51dc2b..dff8ab5a53280 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7814,10 +7814,10 @@ static __init int hardware_setup(void)
> ple_window_shrink = 0;
> }
>
> - if (!cpu_has_vmx_apicv()) {
> + if (!cpu_has_vmx_apicv())
> enable_apicv = 0;
> + if (!enable_apicv)
> vmx_x86_ops.sync_pir_to_irr = NULL;
> - }
>
> if (cpu_has_vmx_tsc_scaling()) {
> kvm_has_tsc_control = true;
>
NACK - the patch is only okay to backport for 5.15
Paolo
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE
[not found] <20211213142020.352376-1-sashal@kernel.org>
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 2/4] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled Sasha Levin
@ 2021-12-13 14:20 ` Sasha Levin
2021-12-13 14:22 ` Paolo Bonzini
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE Sasha Levin
2 siblings, 1 reply; 6+ messages in thread
From: Sasha Levin @ 2021-12-13 14:20 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Vitaly Kuznetsov, Sean Christopherson, Paolo Bonzini, Sasha Levin,
shuah, kvm, linux-kselftest
From: Vitaly Kuznetsov <vkuznets@redhat.com>
[ Upstream commit 908fa88e420f30dde6d80f092795a18ec72ca6d3 ]
With the elevated 'KVM_CAP_MAX_VCPUS' value kvm_create_max_vcpus test
may hit RLIMIT_NOFILE limits:
# ./kvm_create_max_vcpus
KVM_CAP_MAX_VCPU_ID: 4096
KVM_CAP_MAX_VCPUS: 1024
Testing creating 1024 vCPUs, with IDs 0...1023.
/dev/kvm not available (errno: 24), skipping test
Adjust RLIMIT_NOFILE limits to make sure KVM_CAP_MAX_VCPUS fds can be
opened. Note, raising hard limit ('rlim_max') requires CAP_SYS_RESOURCE
capability which is generally not needed to run kvm selftests (but without
raising the limit the test is doomed to fail anyway).
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211123135953.667434-1-vkuznets@redhat.com>
[Skip the test if the hard limit can be raised. - Paolo]
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../selftests/kvm/kvm_create_max_vcpus.c | 30 +++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
index 0299cd81b8ba2..aa3795cd7bd3d 100644
--- a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
+++ b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
@@ -12,6 +12,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/resource.h>
#include "test_util.h"
@@ -40,10 +41,39 @@ int main(int argc, char *argv[])
{
int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID);
int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
+ /*
+ * Number of file descriptors reqired, KVM_CAP_MAX_VCPUS for vCPU fds +
+ * an arbitrary number for everything else.
+ */
+ int nr_fds_wanted = kvm_max_vcpus + 100;
+ struct rlimit rl;
pr_info("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id);
pr_info("KVM_CAP_MAX_VCPUS: %d\n", kvm_max_vcpus);
+ /*
+ * Check that we're allowed to open nr_fds_wanted file descriptors and
+ * try raising the limits if needed.
+ */
+ TEST_ASSERT(!getrlimit(RLIMIT_NOFILE, &rl), "getrlimit() failed!");
+
+ if (rl.rlim_cur < nr_fds_wanted) {
+ rl.rlim_cur = nr_fds_wanted;
+ if (rl.rlim_max < nr_fds_wanted) {
+ int old_rlim_max = rl.rlim_max;
+ rl.rlim_max = nr_fds_wanted;
+
+ int r = setrlimit(RLIMIT_NOFILE, &rl);
+ if (r < 0) {
+ printf("RLIMIT_NOFILE hard limit is too low (%d, wanted %d)\n",
+ old_rlim_max, nr_fds_wanted);
+ exit(KSFT_SKIP);
+ }
+ } else {
+ TEST_ASSERT(!setrlimit(RLIMIT_NOFILE, &rl), "setrlimit() failed!");
+ }
+ }
+
/*
* Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID.
* Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID
--
2.33.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE Sasha Levin
@ 2021-12-13 14:22 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2021-12-13 14:22 UTC (permalink / raw)
To: Sasha Levin, linux-kernel, stable
Cc: Vitaly Kuznetsov, Sean Christopherson, shuah, kvm,
linux-kselftest
On 12/13/21 15:20, Sasha Levin wrote:
> From: Vitaly Kuznetsov <vkuznets@redhat.com>
>
> [ Upstream commit 908fa88e420f30dde6d80f092795a18ec72ca6d3 ]
>
> With the elevated 'KVM_CAP_MAX_VCPUS' value kvm_create_max_vcpus test
> may hit RLIMIT_NOFILE limits:
>
> # ./kvm_create_max_vcpus
> KVM_CAP_MAX_VCPU_ID: 4096
> KVM_CAP_MAX_VCPUS: 1024
> Testing creating 1024 vCPUs, with IDs 0...1023.
> /dev/kvm not available (errno: 24), skipping test
>
> Adjust RLIMIT_NOFILE limits to make sure KVM_CAP_MAX_VCPUS fds can be
> opened. Note, raising hard limit ('rlim_max') requires CAP_SYS_RESOURCE
> capability which is generally not needed to run kvm selftests (but without
> raising the limit the test is doomed to fail anyway).
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Message-Id: <20211123135953.667434-1-vkuznets@redhat.com>
> [Skip the test if the hard limit can be raised. - Paolo]
> Reviewed-by: Sean Christopherson <seanjc@google.com>
> Tested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> .../selftests/kvm/kvm_create_max_vcpus.c | 30 +++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> index 0299cd81b8ba2..aa3795cd7bd3d 100644
> --- a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> +++ b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> @@ -12,6 +12,7 @@
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> +#include <sys/resource.h>
>
> #include "test_util.h"
>
> @@ -40,10 +41,39 @@ int main(int argc, char *argv[])
> {
> int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID);
> int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
> + /*
> + * Number of file descriptors reqired, KVM_CAP_MAX_VCPUS for vCPU fds +
> + * an arbitrary number for everything else.
> + */
> + int nr_fds_wanted = kvm_max_vcpus + 100;
> + struct rlimit rl;
>
> pr_info("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id);
> pr_info("KVM_CAP_MAX_VCPUS: %d\n", kvm_max_vcpus);
>
> + /*
> + * Check that we're allowed to open nr_fds_wanted file descriptors and
> + * try raising the limits if needed.
> + */
> + TEST_ASSERT(!getrlimit(RLIMIT_NOFILE, &rl), "getrlimit() failed!");
> +
> + if (rl.rlim_cur < nr_fds_wanted) {
> + rl.rlim_cur = nr_fds_wanted;
> + if (rl.rlim_max < nr_fds_wanted) {
> + int old_rlim_max = rl.rlim_max;
> + rl.rlim_max = nr_fds_wanted;
> +
> + int r = setrlimit(RLIMIT_NOFILE, &rl);
> + if (r < 0) {
> + printf("RLIMIT_NOFILE hard limit is too low (%d, wanted %d)\n",
> + old_rlim_max, nr_fds_wanted);
> + exit(KSFT_SKIP);
> + }
> + } else {
> + TEST_ASSERT(!setrlimit(RLIMIT_NOFILE, &rl), "setrlimit() failed!");
> + }
> + }
> +
> /*
> * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID.
> * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID
>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE
[not found] <20211213142020.352376-1-sashal@kernel.org>
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 2/4] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled Sasha Levin
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE Sasha Levin
@ 2021-12-13 14:20 ` Sasha Levin
2021-12-13 14:22 ` Paolo Bonzini
2 siblings, 1 reply; 6+ messages in thread
From: Sasha Levin @ 2021-12-13 14:20 UTC (permalink / raw)
To: linux-kernel, stable; +Cc: Paolo Bonzini, Sasha Levin, kvm
From: Paolo Bonzini <pbonzini@redhat.com>
[ Upstream commit 5f25e71e311478f9bb0a8ef49e7d8b95316491d7 ]
This is not an unrecoverable situation. Users of kvm_read_guest_offset_cached
and kvm_write_guest_offset_cached must expect the read/write to fail, and
therefore it is possible to just return early with an error value.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
virt/kvm/kvm_main.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 97ac3c6fd4441..4a7d377b3a500 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2590,7 +2590,8 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
int r;
gpa_t gpa = ghc->gpa + offset;
- BUG_ON(len + offset > ghc->len);
+ if (WARN_ON_ONCE(len + offset > ghc->len))
+ return -EINVAL;
if (slots->generation != ghc->generation) {
if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
@@ -2627,7 +2628,8 @@ int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
int r;
gpa_t gpa = ghc->gpa + offset;
- BUG_ON(len + offset > ghc->len);
+ if (WARN_ON_ONCE(len + offset > ghc->len))
+ return -EINVAL;
if (slots->generation != ghc->generation) {
if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
--
2.33.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE
2021-12-13 14:20 ` [PATCH MANUALSEL 5.10 4/4] KVM: downgrade two BUG_ONs to WARN_ON_ONCE Sasha Levin
@ 2021-12-13 14:22 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2021-12-13 14:22 UTC (permalink / raw)
To: Sasha Levin, linux-kernel, stable; +Cc: kvm
On 12/13/21 15:20, Sasha Levin wrote:
> From: Paolo Bonzini <pbonzini@redhat.com>
>
> [ Upstream commit 5f25e71e311478f9bb0a8ef49e7d8b95316491d7 ]
>
> This is not an unrecoverable situation. Users of kvm_read_guest_offset_cached
> and kvm_write_guest_offset_cached must expect the read/write to fail, and
> therefore it is possible to just return early with an error value.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> virt/kvm/kvm_main.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 97ac3c6fd4441..4a7d377b3a500 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2590,7 +2590,8 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
> int r;
> gpa_t gpa = ghc->gpa + offset;
>
> - BUG_ON(len + offset > ghc->len);
> + if (WARN_ON_ONCE(len + offset > ghc->len))
> + return -EINVAL;
>
> if (slots->generation != ghc->generation) {
> if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
> @@ -2627,7 +2628,8 @@ int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
> int r;
> gpa_t gpa = ghc->gpa + offset;
>
> - BUG_ON(len + offset > ghc->len);
> + if (WARN_ON_ONCE(len + offset > ghc->len))
> + return -EINVAL;
>
> if (slots->generation != ghc->generation) {
> if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
^ permalink raw reply [flat|nested] 6+ messages in thread