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| author | Paolo Bonzini <pbonzini@redhat.com> | 2021-10-12 18:33:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-27 10:59:47 +0300 |
| commit | 3f54362dc7d7a382483fc4872abd4ad97b734609 (patch) | |
| tree | 123f64848b3e8408e778c32d6f48f18f96f5649e /arch/x86/include | |
| parent | 4988e000b3a8fba70cc31ce826829bb6cf8c7838 (diff) | |
| download | linux-3f54362dc7d7a382483fc4872abd4ad97b734609.tar.xz | |
KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if needed
commit 95e16b4792b0429f1933872f743410f00e590c55 upstream.
The PIO scratch buffer is larger than a single page, and therefore
it is not possible to copy it in a single step to vcpu->arch/pio_data.
Bound each call to emulator_pio_in/out to a single page; keep
track of how many I/O operations are left in vcpu->arch.sev_pio_count,
so that the operation can be restarted in the complete_userspace_io
callback.
For OUT, this means that the previous kvm_sev_es_outs implementation
becomes an iterator of the loop, and we can consume the sev_pio_data
buffer before leaving to userspace.
For IN, instead, consuming the buffer and decreasing sev_pio_count
is always done in the complete_userspace_io callback, because that
is when the memcpy is done into sev_pio_data.
Cc: stable@vger.kernel.org
Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest")
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e7fa1c951f6d..471b35d0b121 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -696,6 +696,7 @@ struct kvm_vcpu_arch { struct kvm_pio_request pio; void *pio_data; void *sev_pio_data; + unsigned sev_pio_count; u8 event_exit_inst_len; |