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Commit 5f7dde7b authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
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KVM: x86: Mark bit 7 in long-mode PDPTE according to 1GB pages support 



In long-mode, bit 7 in the PDPTE is not reserved only if 1GB pages are
supported by the CPU. Currently the bit is considered by KVM as always
reserved.

Signed-off-by: default avatarNadav Amit <namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a4ab9d0c

arch/x86/kvm/cpuid.h

+7 −0
Original line number Diff line number Diff line
@@ -88,4 +88,11 @@ static inline bool guest_cpuid_has_x2apic(struct kvm_vcpu *vcpu) 
	return best && (best->ecx & bit(X86_FEATURE_X2APIC));

}



static inline bool guest_cpuid_has_gbpages(struct kvm_vcpu *vcpu)

{

	struct kvm_cpuid_entry2 *best;



	best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);

	return best && (best->edx & bit(X86_FEATURE_GBPAGES));

}

#endif

arch/x86/kvm/mmu.c

+6 −2
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include "mmu.h"

#include "x86.h"

#include "kvm_cache_regs.h"

#include "cpuid.h"



#include <linux/kvm_host.h>

#include <linux/types.h>
@@ -3516,11 +3517,14 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, 
{

	int maxphyaddr = cpuid_maxphyaddr(vcpu);

	u64 exb_bit_rsvd = 0;

	u64 gbpages_bit_rsvd = 0;



	context->bad_mt_xwr = 0;



	if (!context->nx)

		exb_bit_rsvd = rsvd_bits(63, 63);

	if (!guest_cpuid_has_gbpages(vcpu))

		gbpages_bit_rsvd = rsvd_bits(7, 7);

	switch (context->root_level) {

	case PT32_ROOT_LEVEL:

		/* no rsvd bits for 2 level 4K page table entries */
@@ -3557,14 +3561,14 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, 
		context->rsvd_bits_mask[0][3] = exb_bit_rsvd |

			rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7);

		context->rsvd_bits_mask[0][2] = exb_bit_rsvd |

			rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7);

			gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51);

		context->rsvd_bits_mask[0][1] = exb_bit_rsvd |

			rsvd_bits(maxphyaddr, 51);

		context->rsvd_bits_mask[0][0] = exb_bit_rsvd |

			rsvd_bits(maxphyaddr, 51);

		context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3];

		context->rsvd_bits_mask[1][2] = exb_bit_rsvd |

			rsvd_bits(maxphyaddr, 51) |

			gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51) |

			rsvd_bits(13, 29);

		context->rsvd_bits_mask[1][1] = exb_bit_rsvd |

			rsvd_bits(maxphyaddr, 51) |